A stepping motor includes a magnet ring 1 whose outer peripheral surface
is circumferentially divided to form radial protrusions and recesses and
whose outer peripheral surface consists of a cylindrical permanent magnet
magnetized to the same polarity, first and second cylindrical coils 2 and
3, a first outer magnetic pole portion 8 excited by the first coil, a
second outer magnetic pole portion 9 excited by the second coil, and an
output shaft 10 formed of a soft magnetic material and fixed to the inner
peripheral portion of the magnet ring, the output shaft 10 being opposed
to at least one of the first outer magnetic pole portion and the second
outer magnetic pole portion in a predetermined axial range and equipped
with an inner magnetic pole portion excited by at least one of the first
coil and the second coil. Accordingly, a low-cost, high output, and high
resolution stepping motor can be provided without hindering
miniaturization.