The visa application must be submitted, in writing, on the appropriate form in a single copy, filled in completely, signed by the foreigner and accompanied by a passport-size photograph.
The foreigner applying for a visa must, as a rule, after an appointment, which will be granted within a maximum of 15 days, contact the diplomatic-consular Representation in person, also in order to be interviewed about the reasons for and circumstances of the stay and for fingerprints to be taken (Art. 13 and Art. 47 Visa Code).

The applicant must attach to the application form a valid travel document to which the visa can be materially affixed and, where required, supporting documentation.
The applicant is obliged to certify:
– the purpose of the journey
– the means of transport and return
– the means of subsistence during the journey and the stay;
– accommodation conditions.

After assessing the admissibility of the visa application on the basis of the documentation produced by the applicant and what it learns during the interview – which is usually direct and personal – the Representation shall carry out the prescribed preventive security checks, consulting the list of applicants not admissible to the Schengen area by computer or telematic means via the global visa network.

The following are exempt from the visa requirement for stays of up to 90 days, for tourism, mission, business, invitation, sports competition and study:
Albania, Andorra, Antigua and Barbuda, Argentina, Australia, Bahamas, Barbados, Bosnia-Herzegovina, Brazil, Brunei, Canada, Chile, Colombia, South Korea, Costa Rica, Croatia, Dominica, El Salvador, Former Yugoslav Republic of Macedonia (FYROM), United Arab Emirates, Georgia, Japan, Grenada, Guatemala, Honduras, Hong Kong, Solomon Islands, Israel, Kiribati, Malaysia, Macau, Northern Mariana Islands, Marshall Islands, Mauritius, Mexico, Micronesia, Monaco, Montenegro, Nicaragua, New Zealand, Palau, Panama, Paraguay, Peru, Saint Kitts and Nevis, Samoa, Saint Lucia, Serbia, Seychelles, Singapore, United States, St. Vincent and the Grenadines, Taiwan, East Timor, Tonga, Trinidad, Tobago, Tuvalu, Ukraine, Uruguay, Vanatu, Venezuela.

For Taiwanese nationals, the visa requirement exemption applies only to holders of passports including their identity card number.
For citizens of Albania, Bosnia and Herzegovina, Former Yugoslav Republic of Macedonia, Moldova, Montenegro, Serbia the visa requirement exemption applies only to holders of biometric passports.
Serbian citizens holding passports issued by the Serbian Coordination Directorate (in Serbian: Koordinaciona upreva) are excluded from the visa waiver.
Citizens of San Marino, the Holy See and Switzerland are exempt from the visa requirement in all cases.
Source: Ministry of Foreign Affairs

NOTE:
Although nationals of some countries (e.g. Argentina, Brazil, Mexico, Venezuela, etc.), by virtue of bilateral agreements, are not subject to the prior request for a visa for the purpose of short stays (up to a maximum of 90 days per six-month period), they must in any case demonstrate possession of the requirements relating to means of subsistence as set out in the Directive of the Ministry of the Interior of 01/03/2000. When the foreigner enters the Italian State’s national territory, he may be asked by the border police authorities to prove his means of subsistence. Failure to possess these means will result in a formal border refusal order.

Beware, when entering the Schengen Area the border authorities may ask you
– To present your passport valid for at least three months after the planned date of departure from the Schengen Area (re-entry).
– To produce documentation justifying the reasons for and the duration of your stay in Italy.
– To show proof of Schengen health insurance worth 30,000 euros
– To demonstrate the availability of economic means of subsistence or to show a bank or insurance guarantee
– That you have an airline ticket with a return date not exceeding 90 days from the date of entry into the Schengen Area
– Proof of hotel accommodation or declaration of accommodation (ex invitation letter)

To check whether you need a visa to enter Italy, you can consult the visa database on the Ministry of Foreign Affairs website.
By clicking on the question ‘Do you need a visa?’ and filling in the data on Nationality, Residence, Length of Stay and Reason for Visa, foreign citizens can find out if they need a visa to enter Italy and obtain information of a purely indicative (and not exhaustive) nature on the general requirements for applying for one.

https://vistoperitalia.esteri.it/
the site is translated into English, Arabic, Russian and Chinese.

Citizens of the following countries/territorial entities, holders of ordinary passports, are subject to visa requirements for entry into Italy:

Afghanistan, Algeria, Angola, Saudi Arabia, Armenia, Palestinian Authority, Azerbaijan, Bahrain, Bangladesh, Belize, Benin, Bhutan, Belarus, Bolivia, Botswana, Burkina Faso, Burundi, Cambodia, Cameroon, Cape Verde, Central Africa, Chad, China, Comoros, Congo, Congo (Democratic Republic), North Korea, Ivory Coast, Cuba, Dominica, Dominican Republic (Republic), Ecuador, Egypt, United Arab Emirates, Eritrea, Ethiopia, Fiji, the Philippines, Gabon, Gambia, Georgia, Ghana, Jamaica, Djibouti, Jordan, Grenada, Guinea, Guinea Bissau, Equatorial Guinea, Guyana, Haiti, India, Indonesia, Iran, Iraq, Kazakhstan, Kenya, Kyrgyzstan, Kiribati Kosovo, Kuwait, Laos, Lesotho, Lebanon, Liberia, Libya, Madagascar, Malawi, Maldives, Mali, Morocco, Marshall Islands, Mauritania, Micronesia, Myanmar, Moldova, Mongolia, Mozambique, Namibia, Nauru, Nepal, Niger, Nigeria, Oman, Pakistan, Palau, Papua New Guinea, Qatar, Rwanda, Russia, Saint Lucia, Saint Vincent and the Grenadines, Solomon Islands, Western Samoa, Sao Tome and Principe, Senegal, Sierra Leone, Syria, Somalia, Sri Lanka, South Africa, Sudan, Suriname, Swaziland, Tajikistan, Tanzania, Thailand, East Timor, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Tuvalu, Uganda, Uzbekistan, Vanuatu, Vietnam, Yemen, Zambia, Zimbabwe.