To provide a pulse matching circuit capable of outputting a pulse having a reduced noise influence without loading a complicated software.

The pulse width of a pulse output last time is stored, and the pulse width of a pulse input this time is compared with the stored pulse width of the pulse output last time. When the ratio between the pulse width of the pulse input this time and the pulse width of the pulse output last time is a ratio other than a prescribed ratio based on the comparison result, a pulse having the pulse width approximately equal to the pulse width of the pulse output last time is generated, and the generated pulse is replaced with the pulse input this time.