To provide a refrigerator installing structure capable of suppressing an abrupt rise in pressure in a space portion formed between a sleeve and a cylinder.

Disclosed is a refrigerator installing structure that enables a refrigerator R including a cylinder C1, C1 and a displacer D1, D2 to be installed in a vacuum vessel in which an object to be cooled is accommodated, the displacer D1, D2 being removed from the cylinder C1, C2 during maintenance, the refrigerator installing structure being provided with a sleeve 2 housing the cylinder C1, C2 in a state of being insulated from a vacuum area of an empty vessel. The cylinder is movable inside the sleeve 2 between a position at which the cylinder comes in thermal contact with the sleeve and another position at which the thermal contact is released, and includes a safety valve 50 configured to discharge a gas inside a space 60 formed between the sleeve 2 and the cylinder C1, C2 if a pressure inside the space 60 becomes greater than or equal to a predetermined pressure.