A refrigeration cycle device (1) circulates refrigerant, which is a non-azeotropic refrigerant mixture, in a refrigeration cycle in which a compressor (21), a condenser (22), an expansion valve (23) and a vaporizer (24) are connected by refrigerant pipes, wherein during the running of a refrigeration cycle, circulation composition values are calculated on the basis of the states before and after a change in the refrigerant temperature and refrigerant pressure, a dT value that corrects a second temperature sensor (45) and a dP value that corrects a pressure sensor (44) are calculated according to a reference composition value and the circulation composition value of the refrigerant, the temperature value of the refrigerant at the outlet side is corrected using dT, the pressure value of the refrigerant is corrected using dP, and the refrigeration cycle is run.