A stepping motor includes a magnet having a magnetized portion, first and second coils, a first yoke having a first-magnetic-pole portion, a second yoke having a second-magnetic-pole portion, and a rotating yoke having a third-magnetic-pole portion fixed to the single surface of the magnet. The first coil is disposed outside of the outer-circumferential surface of the magnet, and the second coil is disposed inside of the inner-circumferential surface of the magnet so as to have the same concentricity as the magnet. The first and second magnetic-pole portions and the magnetized portion face each other across a certain gap. The cylindrical portion of the first yoke and the outermost-diameter portion of the rotating yoke face each other across a gap in the radial direction, and the cylindrical portion of the second yoke and the flat surface portion of the rotating yoke face each other across a gap in the shaft direction. Thus, an easy-to-assemble low-cost driving device having a thin shape in the shaft direction, and high output with small torque loss is provided.