A motor shaft is configured to be press-fitted into a hole formed in a press-fitted component from a front end side in an axial direction. The motor shaft includes: a shaft body; a first annular projection portion that protrudes outwardly in a radial direction of the shaft body and is brought into contact with an inner circumferential surface of the hole the first annular projection portion being positioned at a first position; and a second annular projection portion that protrudes outwardly in the radial direction of the shaft body and is brought into contact with the inner circumferential surface of the hole, the second annular projection portion being positioned at a second position that is shifted from the first position toward a rear end side in the axial direction of the shaft body.