Abstract: There is provided a stepping motor comprising: a stator assembly; a rotor assembly rotatably disposed inside the stator assembly, and including a rotary shaft rotatably supported by bearings, a sleeve fixedly attached onto the rotary shaft, and at least one magnet disposed outside the sleeve; and a preloading mechanism disposed between the sleeve and one of the bearings, and including a coil spring, and a spring holder which is composed of an outer case shaped in a cup-like configuration and an inner case shaped in a cup-like configuration, and which is adapted to house the coil spring. In the stepping motor described above, the spring holder of the preloading mechanism is formed of reinforced polyamide resin, and a washer member having a high sliladability is disposed between the preloading mechanism and the one bearing.