Abstract: A refrigeration cycle apparatus includes a heat accumulating unit for accumulating an exceess heat generated during the operation of a refrigeration cycle main unit and radiating the accumulated heat at a desired time. The accumulating unit includes a heat accumulating container and latent heat accumulating material housed in the container. The material has a predetermined phase transition temperature and a supercooling state release temperature which is lower than the phase transition temperature. The material maintains a supercooling state at a temperature between the phase transition temperature and the supercooling state release temperature. When the material is cooled by a release mechanism to a temperature below the supercooling state release temperature, the supercooling state of the material is released and the material radiates the accumulated heat. The radiated heat is used for heating the refrigerant to be sent a compressor at the start of the heating or defrosting operation of the main unit.