The invention discloses a refrigeration device for a container. The refrigeration device includes: a refrigerant circuit (20) comprising a main loop (21) formed by interconnecting a compressor (30), a condenser (31), a main expansion valve (32) and an evaporator (33) sequentially, and a hot gas bypass circuit (22) for bypassing the condenser (31) and the main expansion valve (32) to convey a compressed refrigerant from the compressor (30) to the evaporator (33), and performing a refrigeration cycle; and a compressor control unit (81) controlling the operating rotational frequency of the compressor (30) such that the pressure of the compressed refrigerant from the compressor (30) reaches a target value during the defrosting operation for defrosting the evaporator (33) in a circulating flow in which the compressed refrigerant from the compressor (30) returns to the compressor (30) via the hot gas bypass circuit (22) and the evaporator (33).