When a refrigerant which is mainly hydro-fluoro-olefins is used in a refrigeration cycle device, a metal which forms the cycle acts as a catalyst and decomposes and polymerises refrigerant comprising refrigerating oil and carbon double bonds, and there is a possibility of a drop in refrigerating ability due to compressor break-down or a loss of refrigerant flow amount in the refrigeration cycle. A refrigerant and a refrigerating oil (103) are sealed in a hermetically sealed container (101); the refrigerant is either hydro-fluoro-olefins having carbon double bonds in the composition thereof, or a mixture of hydro-fluoro-olefins which do not have carbon double bonds, with hydro-fluoro-olefins as a base component; the refrigerating oil (103) contains at least one kind from among benzotriazole, dialkyldithiophosphate zinc, dialkyl selenium, metal phenates and organic nitrogen compounds.