To solve a problem in a refrigerating cycle found when a refrigerant flow channel is long and a gap is large, that as a returning speed of a lubricant is lowered, and the returning amount is reduced, the amount of lubricant in the compressor can not be properly kept, and the reliability of the compressor is degraded.

This refrigerating cycle evaluation system connected with the refrigerating cycle 1 comprising at least the compressor 11a lubricated by the lubricant and compressing the refrigerant, a condenser 11c condensing the compressed refrigerant, an expansion valve 11d expanding the refrigerant, an evaporator 12a for evaporating the refrigerant passing through the expansion valve 11d, and a refrigerant pipe conduit 13 connecting the compressor 11a, the condenser 11c, the expansion valve 11d and the compressor 11a so that the refrigerant successively passes therethrough, further comprises a lubricant separating mechanism 22 for separating the lubricant and the refrigerant, a lubricant storing mechanism 25 capable of storing the separated lubricant by the amount corresponding to the amount of lubricant accumulated in the refrigerant pipe conduit 13 of the refrigerating cycle 1 to be evaluated, a lubricant storage amount control mechanism for controlling the amount of lubricant stored in the lubricant storing mechanism 25, and a lubricant returning amount control mechanism 3 for controlling the returning amount to the refrigerating cycle 1, of the stored lubricant.