PURPOSE: To enhance an effective printing speed by a method wherein during a head-up running time for running a carriage with a thermal head separated from a platen the carriage is traveled in a carriage return time for returning the carriage to an initial printing position at a speed higher than that in a printing time.

CONSTITUTION: In a carriage return time for returning a carriage 6 to an initial printing position, a printing by a thermal head 5 is not conducted and, thus, a control signal is outputted from a CPU 21 to a voltage change-over means 24. By the voltage change-over means 24, a DC power (high-tension electric current) 27 of high voltage and high frequency is outputted to a carriage drive motor 10. Therefore, in this mode, a direct current is not supplied to the thermal head 5. In this state, a large number of pulses are inputted to the carriage drive motor 10 per unit time in comparison with a printing time to rotate the motor 10 at a speed higher than that in printing, whereby the carriage 6 is returned to the initial printing position in a direction reverse to a direction of an arrow A at a higher running speed than that in printing.