What visa you need for visiting Finland depends on your nationality and purpose.
Most Western nationals don’t need a tourist visa for stays of less than three-month in the Nordic countries. Among those nationalities who need a Schengen visa are Chinese and Indians. When you travel to Finland, you need a valid national passport or another equivalent official document that establishes your identity and nationality satisfactorily.
Finland is a member of the European Union`s Schengen agreement, meaning that passport controls are eliminated between Schengen countries in Europe. You do not have to stop or show a passport if you are travelling between Finland and Sweden and Finland and Norway as a citizen from a Schengen country. You still have to bring your passport if you need to prove your identity.
Following countries are a member of the European Union Schengen Agreement: Austria, Belgium, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Italy, Latvia, Liechtenstein, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden and Switzerland.
If you are not a citizen of Finland or another European Economic Area (EEA) country, you may also need a visa.
See more: Visa to the Nordic Countries