A refrigerator (300, 400) comprising: a refrigerator body (20, 200) having a heat insulation box (21, 201) and a heat insulation wall (24, 204); a plurality of storage compartments; a machine compartment (60, 230) disposed on a back surface side of the heat insulation box (21, 201); a refrigeration cycle including at least a compressor (50, 220); and a controller (70, 240) which controls operation of the compressor (50, 220), wherein the compressor (50, 220) and the controller (70, 240) are disposed in the machine compartment (60, 230), the machine compartment (60, 230) is disposed opposed to the storage compartment disposed at an uppermost portion of the refrigeration body (20, 200), with the heat insulation wall (24, 204) interposed therebetween, at least the storage compartment disposed at the uppermost portion of the refrigeration body (20, 200) is set to a cooling temperature zone, and the machine compartment (60, 230) is disposed in an upper portion of the back surface of the storage compartment disposed at the uppermost portion of the refrigeration body (20, 200), a combustible refrigerant is used as a refrigerant that circulates through the refrigeration cycle, wherein the compressor (50, 220) includes a discharge pipe (50a, 220a) from which a high-temperature and high-pressure refrigerant is discharged and a suction pipe (50b, 220b) into which the refrigerant flows, a machine compartment cover (80, 250) is provided on at least a back surface of the machine compartment (60, 230), the machine compartment cover (80, 250) has ventilation openings (80a, 250a) which communicate inside and outside of the machine compartment (60, 230), characterized in that the suction pipe (50b, 220b) is disposed closer to the controller (70, 240) than the discharge pipe (50a, 220a) in the machine compartment (60, 230), the ventilation openings (80a, 250a) are provided at least at a lower portion of the machine compartment cover (80, 250) in the vicinity of the controller (70, 240) and the suction pipe (50b, 220b), and at least at an upper portion of the machine compartment cover (80, 250) in the vicinity of the discharge pipe (50a, 220a) and the compressor (50, 220). a refrigerator body (20, 200) having a heat insulation box (21, 201) and a heat insulation wall (24, 204); a plurality of storage compartments; a machine compartment (60, 230) disposed on a back surface side of the heat insulation box (21, 201); a refrigeration cycle including at least a compressor (50, 220); and a controller (70, 240) which controls operation of the compressor (50, 220), wherein the compressor (50, 220) and the controller (70, 240) are disposed in the machine compartment (60, 230), the machine compartment (60, 230) is disposed opposed to the storage compartment disposed at an uppermost portion of the refrigeration body (20, 200), with the heat insulation wall (24, 204) interposed therebetween, at least the storage compartment disposed at the uppermost portion of the refrigeration body (20, 200) is set to a cooling temperature zone, and the machine compartment (60, 230) is disposed in an upper portion of the back surface of the storage compartment disposed at the uppermost portion of the refrigeration body (20, 200), a combustible refrigerant is used as a refrigerant that circulates through the refrigeration cycle, wherein the compressor (50, 220) includes a discharge pipe (50a, 220a) from which a high-temperature and high-pressure refrigerant is discharged and a suction pipe (50b, 220b) into which the refrigerant flows, a machine compartment cover (80, 250) is provided on at least a back surface of the machine compartment (60, 230), a machine compartment cover (80, 250) is provided on at least a back surface of the machine compartment (60, 230), the machine compartment cover (80, 250) has ventilation openings (80a, 250a) which communicate inside and outside of the machine compartment (60, 230), characterized in that the suction pipe (50b, 220b) is disposed closer to the controller (70, 240) than the discharge pipe (50a, 220a) in the machine compartment (60, 230), the ventilation openings (80a, 250a) are provided at least at a lower portion of the machine compartment cover (80, 250) in the vicinity of the controller (70, 240) and the suction pipe (50b, 220b), and at least at an upper portion of the machine compartment cover (80, 250) in the vicinity of the discharge pipe (50a, 220a) and the compressor (50, 220).