The article presents the results of mycological analysis of samples taken from open surfaces in residential and working areas of the Arctic and Antarctic Research Institute (AARI) station on the Bolshevik island of the Northern Land archipelago. 114 samples were studied during the expedition work from 2014 to 2016. In total, 47 species of micromycetes were detected in the course of the research. Most of the species (89%) were identified as Ascomycetes. Mucor group of fungi was composed 11% out of all the identified species. The genus Penicillium was the richest in species diversity (16 species). On the surface of materials in places of the increased moisture, there was an open growth of colonies of the Penicillium species. P. expansum was the dominant one, being noted during all the years of observations with the occurrence of about 60%. Among the frequently occurring species, there were P. brevicompactum, P. herqueri, P. purpurogenum and P. waksmanii, which were also noted during all the years of observation