The law abolishes the total ban on nuclear weapons on Finnish soil.
The government proposed deleting a section that banned the import, manufacture, possession and detonation of nuclear weapons, saying the restriction prevented Finland from fully benefiting from the deterrent effect of nuclear weapons.
The government also proposed that Finland does not intend to station nuclear weapons on its territory in peacetime.
The vote on Wednesday was 125 to 61, with 13 members absent.
