Referred to is a flag pattern in an interrupt activation condition flag storing unit which stores an event as an interrupt activation condition flag. As a result thereof, it is determined whether or no the flag pattern exists in an operational key description storing unit which stores the position for the operation corresponding to the flag pattern n the interrupt activation condition flag storing unit. As a result of the determination, an interrupt process is performed in accordance with an operational description storing unit which stores a process corresponding to the flag pattern if the pattern exits. Thereafter, bit for the flag corresponding to the executed process is cleared out.