A centrifugal compressor having a diffuser structure in which gas flow is less likely to be separated from a hub-side wall surface on the downstream side in a diffuser path. The diffuser path (15) recovers static pressure by reducing the speed of gas flow discharged from the outer peripheral edge of an impeller rotating in a housing (11). The hub-side wall surface (15b) of the diffuser path (15) has a tilt flat surface (20) approaching the shroud side, and the tilt surface (20) is located at a position on the downstream side of that portion of the hub-side wall surface (15b) that is in parallel with the direction normal to a cross-section of an impeller exit.
