PURPOSE: To contrive to reduce a cost by decreasing the total number of circuits through causing a plurality of piezo printing heads to hold one common driving circuit in common.

CONSTITUTION: Data driving circuits 3-1 to 3-n are ON or OFF according to data signals 1-1 to 1-n to control a current flowing through piezo printing heads 6-1 to 6-n to drive the piezo printing heads. When all data signals 1-1 to 1-n are OFF, a common signal control circuit 2 turns ON a common driving circuit 7. Then, electric charge stored in the piezo printing heads 6-1 to 6-n goes through diodes 5-1 to 5-n and passes the common driving circuit 7 and a resistance 8 so as to be earthed to turn OFF all piezo printing heads 6-1 to 6-n. Further, current suppressor resistances 4-1 to 4-n suppress an overcurrent to the piezo printing heads 6-1 to 6-n and the diodes 5-1 to 5-n respectively hinder the inflow of a current from piezo printing heads other than corresponding piezo printing heads.