PURPOSE: To provide a program operation monitoring circuit for which flexibility at the time of monitoring whether or not an optional address is periodically accessed and monitoring the abnormality of a CPU such as runaway or the like is improved.

CONSTITUTION: This program operation monitoring circuit stores address data on an address bus in a buffer register 11, stores the set optional address data in a register 12, compares the address data stored in the buffer register 11 with the address data stored in the register 12 by a comparator means 21, accesses a monitoring timer 24 based on coincidence signals outputted from the comparator means 21 at the time of coincidence and monitors the operation of the CPU.