There is disclosed a refrigerating apparatus which can more efficiently cool the inside of a chamber to an ultralow temperature. In a refrigerating apparatus R1 which condenses a refrigerant discharged from a compressor 14, reduces a pressure of the refrigerant by a capillary tube 18 and evaporates the refrigerant by an evaporator 13 to exert a cooling function, the capillary tube 18 is passed through a suction piping line 32 through which the refrigerant returning from the evaporator 13 to the compressor 14 flows, to constitute a double tube structure. Furthermore, the suction piping line 32 (a piping line 32A) formed in the double tube structure by passing the capillary tube 18 therethrough is surrounded with an insulating material 35.