A centrifugal compressor includes: a rotor that includes a shaft rotatably disposed inside a casing and impellers fixed to an outer periphery of the shaft; a diaphragm that surrounds the impellers from an outer peripheral side; a suction-side casing head disposed separately from the diaphragm on a side on which fluid is sucked; a temperature controlling mechanism that is provided inside the suction-side casing head and is configured to control ambient temperature through flow of a heating medium; a heat insulating body disposed between the suction-side casing head and the diaphragm; and a locking structure that locks the heat insulating body and the suction-side casing head with each other to be relatively displaceable in a radial direction.