A stepping motor comprising a stator and a rotor rotationally driven by the stator, further comprising: a detection rotor for detecting a rotation position of the rotor, wherein the detection rotor is rotatably disposed on a co-axial center with the rotor, and rotationally drivable by the rotor via a rotation drive mechanism between the rotor and the detection rotor, wherein the rotation drive mechanism has a drive play having a predetermined length interval or angle interval in a rotation direction, wherein the rotation drive mechanism comprises a plurality of projections (57b, 57c) of one of the rotor and the detection rotor, the projections (57b, 57c) being separated by the predetermined length interval or the predetermined angle interval in the rotation direction, and another projection of the other one of the detection rotor and the rotor, the other projection being disposed between the plurality of projections (57b, 57c) in the rotation direction, wherein a drive force is transmittable from the rotor to the detection rotor by contact via one of the projections (57b, 57c) of the plurality of projections (57b, 57c) and the other projection for rotating in one direction, and wherein a drive force is transmittable from the rotor to the detection rotor by contact via the other one of the projections (57b, 57c) of the plurality of projections (57b, 57c) and the other projection for rotating in a reverse direction opposite to the one direction, the stepping motor further comprising: a rotation stop mechanism for stopping the rotation of the rotor in the one direction, wherein the predetermined length interval or angle interval of the drive play of the rotation drive mechanism is equal to or greater than a reversion length or a reversion angle of the rotor, by which the rotor reverses in the reverse direction opposite to the one direction when - after the rotation of the rotor is stopped by the rotation stop mechanism - drive pulse signals continue to be supplied to the stator making a phase of a magnetic pole of the stator changing and attracting the rotor. a detection rotor for detecting a rotation position of the rotor, wherein the detection rotor is rotatably disposed on a co-axial center with the rotor, and rotationally drivable by the rotor via a rotation drive mechanism between the rotor and the detection rotor, wherein the rotation drive mechanism has a drive play having a predetermined length interval or angle interval in a rotation direction, wherein the rotation drive mechanism comprises a plurality of projections (57b, 57c) of one of the rotor and the detection rotor, the projections (57b, 57c) being separated by the predetermined length interval or the predetermined angle interval in the rotation direction, and another projection of the other one of the detection rotor and the rotor, the other projection being disposed between the plurality of projections (57b, 57c) in the rotation direction, wherein a drive force is transmittable from the rotor to the detection rotor by contact via one of the projections (57b, 57c) of the plurality of projections (57b, 57c) and the other projection for rotating in one direction, and wherein a drive force is transmittable from the rotor to the detection rotor by contact via the other one of the projections (57b, 57c) of the plurality of projections (57b, 57c) and the other projection for rotating in a reverse direction opposite to the one direction, the stepping motor further comprising: a rotation stop mechanism for stopping the rotation of the rotor in the one direction, wherein the predetermined length interval or angle interval of the drive play of the rotation drive mechanism is equal to or greater than a reversion length or a reversion angle of the rotor, by which the rotor reverses in the reverse direction opposite to the one direction when - after the rotation of the rotor is stopped by the rotation stop mechanism - drive pulse signals continue to be supplied to the stator making a phase of a magnetic pole of the stator changing and attracting the rotor. a rotation stop mechanism for stopping the rotation of the rotor in the one direction, wherein the predetermined length interval or angle interval of the drive play of the rotation drive mechanism is equal to or greater than a reversion length or a reversion angle of the rotor, by which the rotor reverses in the reverse direction opposite to the one direction when - after the rotation of the rotor is stopped by the rotation stop mechanism - drive pulse signals continue to be supplied to the stator making a phase of a magnetic pole of the stator changing and attracting the rotor.