This atlas is based on information in museum collections, literature, databases and unpublished data. In the last 150 years, the number of bat species in Finland increased from six to thirteen. Of these, five are common and regularly breeding (Eptesicus nilssonii, Myotis brandtii, Myotis daubentonii, Myotis mystacinus, Plecotus auritus), and eight rare (Eptesicus serotinus, Myotis dasycneme, Myotis nattereri, Nyctalus noctula, Pipistrellus nathusii, Pipistrellus pipistrellus, Pipistrellus pygmaeus, Vespertilio murinus), of which breeding of two (M. nattereri, P. nathusii) have been confirmed. The total number of records in the study is 11 234, of which 9717 are identified to species. The records are from 940 (25%) 10-km2 squares of Finland's land area. Of the records, 89% are new (1993–2014). Of the recorded bat species, only Eptesicus nilssonii occurs in each of the 21 biogeographical provinces. A decreasing south–north gradient in species richness and abundance exists which may be related to research efforts that are clearly higher in the south.