A lubricating oil for compression-type refrigerators using a refrigerant containing pentafluoroethane which lubricating oil comprises a polyvinyl ether compound having (a) a constituting unit represented by general formula (I): or a polyvinyl ether compound having constituting unit (a) and (b) a constituting unit represented by general formula (I′): (wherein R represents a hydrocarbon group which has 1 to 3 carbon atoms and may have ether bond in the group, and R′ represents a hydrocarbon group which has 3 to 20 carbon atoms and may have ether bond in the group) as the main component. The above lubricating oil shows excellent compatibility with hydrofluorocarbon refrigerants containing pentafluoroethane which can replace chlorofluorocarbons causing environmental pollution, has a high volume intrinsic resistance, and exhibits excellent stability and lubricating property.