An outer mirror includes: a mirror base which is attached to a side surface of a vehicle body of a vehicle; a shaft which is erected on the mirror base; and a mirror housing which is rotatably attached to the shaft and is provided with a mirror for reflecting a rearward of the vehicle body. The shaft is exposed in a gap between a top surface of the mirror base and a bottom surface of the mirror housing. The shaft includes at least one of a concave portion or a convex portion on a part of an outer circumferential surface of the shaft which faces to a front side of the vehicle body.