PURPOSE: To enhance printing quality in starting even at a low temperature to obtain good starting characteristics, by providing a drive circuit supplying a current, prior to printing, to the coil in a wire dot head reverse to the current when printing.

CONSTITUTION: A current i0 reversely flows in the drive circuit in a wire dot head by turning input terminals 1c, 1d ON, e.g., when the power supply of a dot printer is ON. The current i1, which flows in a coil 6 in the wire dot head reverse to when printing, heats the coil 6 without driving the wire dot head. Input terminal 1aW1d is in the OFF condition in the time t1, t2, t4, and t5. Accordingly, the reverse current heats the coil without driving the wire dot head to lower the viscosity of the ink with which the gap between the printing wire and the wire guide are clogged, ensuring printing to be performed form the first character in the printing data sent just after a data present signal.