The monastery itself, the church and library were not damaged by the fire. The building that went up in flames housed farming equipment including the religious community's tractor and snow plough.
According to the head of the monastery, Archimandrite Sergei, the fire caused losses of around half a million euros.
Suspected arson
Later during the night, fire fighters also responded to a blaze at a disused school about 10 kilometres from the Valamo monastery.
Officials say that the building destroyed by the fire was unoccupied. An investigation into both fires and a possible link is to start on Thursday. Local fire chief Ismo Vihro told Yle it is possible that the school fire was a case of arson.
There was another serious fire at the monastery less than two years ago.