PURPOSE: To contrive to enhance efficiency and printing speed of a printing head, by constituting an armature of an armature base and an armature auxiliary plate formed of a high tensile strength material, fixed to the base and engaged with a wire.

CONSTITUTION: The armature auxiliary plate 14 formed of a thin high tensile strength material such as spring steel is fixed to the armature base 13 consisting of 3% silicon steel by brazing, laser welding or the like to constitute the armature 12. The width of the auxiliary plate 14 is reduced toward the tip thereof, the tip is made to be an engaging part 14a for the wire 5, and both side parts are made to be reinforcing bent parts 14b. Since the weight of the base 13 made to have a required minimum size constitutes a major part of the weight of the armature 12, the moment of inertia of the armature 12 can be made to be extremely small, and it can be contrived to enhance the printing speed of the printing head.