A refrigeration device is provided with: a casing body (21) attached to an opening (14) in one end of a box-shaped cooling chamber (11) so as to close the opening (14); a refrigeration cycle unit (30) having a compressor (31) and a radiator (32) which are provided on the side of the casing body (21) which is outside the cooling chamber, and also having an evaporator (35) which is provided on the side of the casing body (21) which is inside the cooling chamber; a diagnostic operation executing unit (81) for controlling the refrigeration cycle unit (30) and executing a diagnostic operation for diagnosing the performance of the cooling chamber (11); and a performance determining unit (82) for determining the performance of the cooling chamber (11) during the diagnostic operation.
