A centrifugal compressor comprising an impeller and a housing, wherein the housing includes: a scroll part having a scroll passage of a spiral shape formed on an outer peripheral side of the impeller; and a diffuser part including a pair of passage walls spaced from each other in an extension direction of a rotational axis of the impeller, the diffuser part forming a diffuser passage between the pair of passage walls, the diffuser passage communicating with the scroll passage along a circumferential direction of the scroll passage on a radially inner side of the scroll part, wherein the pair of passage walls includes: a first passage wall; and a second passage wall positioned closer to a scroll center (O s) of the scroll passage than the first passage wall is to the scroll center (O s) in the extension direction of the rotational axis, wherein the second passage wall includes a radially inner portion (5a2) of an inner wall surface of the scroll passage, and the radially inner portion (5a2) of the inner wall surface included in the second passage wall forms at least one concave arc portion having a curvature center inside the scroll passage in a cross-section of the housing formed by a plane that includes the rotational axis, wherein the at least one concave arc portion includes a radially outermost concave arc portion located outermost in a radial direction of the impeller, and an inclination angle (α) between a tangential direction of a radially outer edge (24a1) of the radially outermost concave arc portion and a direction perpendicular to the rotational axis has a distribution along the circumferential direction of the scroll passage, characterised in that, when a circumferential position in the scroll passage from a tongue of the scroll part to an outlet of the scroll passage is represented by a central angle (θ) about the rotational axis by using the tongue as a reference, the distribution of the inclination angle (α) has a minimum value in a range of the central angle (θ) of 30° to 120°. wherein the housing includes: a scroll part having a scroll passage of a spiral shape formed on an outer peripheral side of the impeller; and a diffuser part including a pair of passage walls spaced from each other in an extension direction of a rotational axis of the impeller, the diffuser part forming a diffuser passage between the pair of passage walls, the diffuser passage communicating with the scroll passage along a circumferential direction of the scroll passage on a radially inner side of the scroll part, a scroll part having a scroll passage of a spiral shape formed on an outer peripheral side of the impeller; and a diffuser part including a pair of passage walls spaced from each other in an extension direction of a rotational axis of the impeller, the diffuser part forming a diffuser passage between the pair of passage walls, the diffuser passage communicating with the scroll passage along a circumferential direction of the scroll passage on a radially inner side of the scroll part, wherein the pair of passage walls includes: a first passage wall; and a second passage wall positioned closer to a scroll center (O s) of the scroll passage than the first passage wall is to the scroll center (O s) in the extension direction of the rotational axis, a first passage wall; and a second passage wall positioned closer to a scroll center (O s) of the scroll passage than the first passage wall is to the scroll center (O s) in the extension direction of the rotational axis, wherein the second passage wall includes a radially inner portion (5a2) of an inner wall surface of the scroll passage, and the radially inner portion (5a2) of the inner wall surface included in the second passage wall forms at least one concave arc portion having a curvature center inside the scroll passage in a cross-section of the housing formed by a plane that includes the rotational axis, wherein the at least one concave arc portion includes a radially outermost concave arc portion located outermost in a radial direction of the impeller, and an inclination angle (α) between a tangential direction of a radially outer edge (24a1) of the radially outermost concave arc portion and a direction perpendicular to the rotational axis has a distribution along the circumferential direction of the scroll passage, characterised in that, when a circumferential position in the scroll passage from a tongue of the scroll part to an outlet of the scroll passage is represented by a central angle (θ) about the rotational axis by using the tongue as a reference, the distribution of the inclination angle (α) has a minimum value in a range of the central angle (θ) of 30° to 120°.