A centrifugal compressor comprising: a casing which forms an impeller inlet flow path, an impeller flow path, an impeller outlet flow path, and a scroll; and an impeller which is disposed in the impeller flow path, wherein the casing is provided with a casing main body, and a heat conduction inhibiting part (16, 116, 216) which is disposed to heat conduction paths to the impeller inlet flow path from at least the impeller outlet flow path and the scroll so as to inhibit heat conduction to the impeller inlet flow path from at least the impeller outlet flow path and the scroll, wherein the heat conduction inhibiting part (16, 116, 216) is formed of a material having heat conductivity lower than that of the casing main body, and wherein the heat conduction inhibiting part (16, 116, 216) is formed of carbon fiber reinforced plastic or glass fiber reinforced plastic, the centrifugal compressor characterized in that the heat conduction inhibiting part (16, 116, 216) includes a main body (24, 124, 224) and an inlet flow path forming portion (25, 125, 225), the inlet flow path forming portion (25, 125, 225) forms an impeller inlet flow path, the impeller inlet flow path includes an inclined portion of which a flow-path area is gradually reduced by approaching the impeller and a normal portion which is disposed on a side closer to the impeller than the inclined portion and of which a flow-path area does not change, and the main body (24, 124, 224) includes a protrusion having a through-hole, the main body (24, 124, 224) being fixed to the casing via the through-hole. a casing which forms an impeller inlet flow path, an impeller flow path, an impeller outlet flow path, and a scroll; and an impeller which is disposed in the impeller flow path, wherein the casing is provided with a casing main body, and a heat conduction inhibiting part (16, 116, 216) which is disposed to heat conduction paths to the impeller inlet flow path from at least the impeller outlet flow path and the scroll so as to inhibit heat conduction to the impeller inlet flow path from at least the impeller outlet flow path and the scroll, a casing main body, and a heat conduction inhibiting part (16, 116, 216) which is disposed to heat conduction paths to the impeller inlet flow path from at least the impeller outlet flow path and the scroll so as to inhibit heat conduction to the impeller inlet flow path from at least the impeller outlet flow path and the scroll, wherein the heat conduction inhibiting part (16, 116, 216) is formed of a material having heat conductivity lower than that of the casing main body, and wherein the heat conduction inhibiting part (16, 116, 216) is formed of carbon fiber reinforced plastic or glass fiber reinforced plastic, the centrifugal compressor characterized in that the heat conduction inhibiting part (16, 116, 216) includes a main body (24, 124, 224) and an inlet flow path forming portion (25, 125, 225), the inlet flow path forming portion (25, 125, 225) forms an impeller inlet flow path, the impeller inlet flow path includes an inclined portion of which a flow-path area is gradually reduced by approaching the impeller and a normal portion which is disposed on a side closer to the impeller than the inclined portion and of which a flow-path area does not change, and the main body (24, 124, 224) includes a protrusion having a through-hole, the main body (24, 124, 224) being fixed to the casing via the through-hole.