A compressor housing for accommodating an impeller, the compressor housing comprising a suction port for drawing air toward the impeller and a scroll passage, which is located about the impeller and extends in the circumferential direction of the impeller, wherein a side in the axial direction of the impeller that is close to the suction port is defined as a distal side of the compressor housing, and a side farther from the suction port is defined to a proximal side, the compressor housing being characterized by: a scroll member having a tubular suction portion, which forms the suction port, a scroll wall portion, which forms a distal-side wall surface of the scroll passage, and an outer wall portion, which extends toward the proximal side from the scroll wall portion, the outer wall portion being located outside of the scroll passage in the radial direction of the impeller and extending in the circumferential direction of the impeller; a shroud member having a fitting portion and a shroud portion, wherein the fitting portion is fitted to the suction portion of the scroll member, and the shroud portion has a first proximal-side wall surface of the scroll passage, which is located on the proximal side of the inner circumference of the scroll passage, a shroud surface, which faces the impeller, and a diffuser surface, which extends from the shroud surface toward the scroll passage; and an annular member, which includes an outer circumferential surface and a second proximal-side wall surface of the scroll passage, which is located on the proximal side of the outer circumference of the scroll passage, the annular member being fitted to the outer wall portion of the scroll member such that the outer circumferential surface of the annular member contacts the inner side of the outer wall portion, wherein the compressor housing is formed by assembling the scroll member, the shroud member, and the annular member together, and the scroll member includes a first positioning portion, which contacts the shroud member to determine the position of the shroud member in relation to the scroll member in the circumferential direction of the impeller, and a second positioning portion, which contacts the annular member to determine the position of the annular member in relation to the scroll member in the circumferential direction of the impeller, the compressor housing being characterised by the first positioning portion and the second positioning portion being formed at the same position in the circumferential direction of the impeller. a scroll member having a tubular suction portion, which forms the suction port, a scroll wall portion, which forms a distal-side wall surface of the scroll passage, and an outer wall portion, which extends toward the proximal side from the scroll wall portion, the outer wall portion being located outside of the scroll passage in the radial direction of the impeller and extending in the circumferential direction of the impeller; a shroud member having a fitting portion and a shroud portion, wherein the fitting portion is fitted to the suction portion of the scroll member, and the shroud portion has a first proximal-side wall surface of the scroll passage, which is located on the proximal side of the inner circumference of the scroll passage, a shroud surface, which faces the impeller, and a diffuser surface, which extends from the shroud surface toward the scroll passage; and an annular member, which includes an outer circumferential surface and a second proximal-side wall surface of the scroll passage, which is located on the proximal side of the outer circumference of the scroll passage, the annular member being fitted to the outer wall portion of the scroll member such that the outer circumferential surface of the annular member contacts the inner side of the outer wall portion, wherein the compressor housing is formed by assembling the scroll member, the shroud member, and the annular member together, and the scroll member includes a first positioning portion, which contacts the shroud member to determine the position of the shroud member in relation to the scroll member in the circumferential direction of the impeller, and a second positioning portion, which contacts the annular member to determine the position of the annular member in relation to the scroll member in the circumferential direction of the impeller, the compressor housing being characterised by the first positioning portion and the second positioning portion being formed at the same position in the circumferential direction of the impeller.