PURPOSE: To decrease the number of components and to attain small size and high performance, by arranging a fulcrum of movement of a moving part having a coil on a hollow center shaft of a cylindrical magnetic substance forming poles axially and inducing a voltage in the coil with magnetic flux component orthogonal to the center shaft.

CONSTITUTION: On a center shaft P of a hollow part 12 of a ring magnet 11 having poles toward the axis center P and being a cylindrical magnetic substance, an armature 15 as a moving part having a coil, a cantilever 13, and a fulcrum of movement of a stylus 14 are arranged and a voltage is induced to coils 26a∼26d with the magnetic flux component in parallel with the direction orthogonal to the center axis P. Since the voltage is induced in the coils by effectively using the magnetic flux density distribution and the direction of magnetic flux formed with the cylindrical magnetic substance 11, a cartridge with simple constitution and high performance can be obtained, without use of conventional yoke for magnetic circuit formation.