Saari killed 10 people in Kauhajoki before shooting himself
Finland has introduced stricter rules on gun permits, following a school shooting in which 11 people died.
Handgun permits would no longer be granted to first-time applicants, the interior ministry said.
Instead, they must train for at least a year at a gun club before being allowed to apply for a permit.
All applicants must also provide a note from a doctor about their mental health and sit an interview with police. The new rules cover pistols and revolvers.
The new guidelines were issued to police on Monday.
The government also is planning to amend Finland's gun law - one of the most liberal in Europe - to enable police to perform more thorough background checks on applicants for gun permits.
Prime Minister Matti Vanhanen has said the country should consider banning private handguns.
The measures were prompted by last week's attack in a college in the western town of Kauhajoki.
Matti Juhani Saari, aged 22, shot nine fellow students and a teacher, before turning his gun on himself.
The murders took place less than a year after another school shooting in which nine people died, including the killer.
Finns have the third highest ratio of gun ownership in the world, after the US and Yemen, according to an international survey of small arms carried out in 2007.