PURPOSE: To provide a step motor driving circuit in which a shortest delay time necessary for prevention of through current can be set even when the switching element is replaced.

CONSTITUTION: When a switching element comprising a MOSFET is replaced, for example, following learning is executed at a control section 40. In other words, when an overcurrent is detected by an overcurrent detecting circuit 61, the delay time Td is incremented by a predetermined amount ΔT at a time. When detection of the overcurrent eventually ends, control is executed based on the Td at that time. When overcurrent is not detected by the overcurrent detection circuit 61, the Td is decremented by a predetermined amount ΔT/2 at a time. If an overcurrent is detected due to decrement of the Td, the Td is incremented by the predetermined amount ΔT and the learning is ended thus executing the control.