An impeller 40 includes a disk 41 having a disk shape centered on an axis O, a plurality of blades 42 provided on a disk main surface 413 of the disk 41 facing a first side Dau in an axial direction Da at intervals in a circumferential direction around the axis O, and a cover 43 that covers the plurality of blades 42 from the first side Dau and gradually expands in diameter from the first side Dau toward a second side Dad in the axial direction. The cover 43 has a thick portion 49 at a position distant from a first end portion 431 positioned closest to the first side, the thick portion having a thickness greater than the thickness of the first end portion 431.