PURPOSE: To effectively economize the power especially in such a case that a printing standby time is long by limiting the supply of power to a printer during the non-printing operation of the printer.

CONSTITUTION: When the printing data Sa from a computer 4 or a buffer circuit 5 is inputted to an input signal detection circuit 11, a detection signal Sb is outputted to a timer circuit 12 to count 3min and, when the printing data Sa is not again inputted, a current control signal Sc is outputted until the next detection signal Sb is inputted and a current control circuit 13 limits the power Vw from a power supply 2 on the basis of the current control signal Sc to supply a current to a printer circuit 3. In this case, the current control circuit 13 turns a switch OFF to drop voltage through a parallel-connected resistor and limits the power Vw to supply a current to the printer circuit 3.