To clean a thermal head on the way of a recording operation by moving a cleaning sheet having an uneven surface of a specific Bekk smoothness or below while bringing the head into pressure contact with the sheet through an ink ribbon.

The thermal head 5 is brought into pressure contact with a cleaning sheet 7 having an uneven surface of a Bekk smoothness of 20 sec or below through an ink ribbon 3, and the sheet 7 is moved while holding the contact state as it is. According to this cleaning method, since a heating part 6 of the head 5 is brought into pressure contact with the uneven surface of the sheet 7 through the ribbon 3, when the sheet 7 is conveyed while holding the contact state as it is, the uneven surface is moved while being engaged with a deposit adhered to the part 6 to take off the deposit. Then, since the uneven surface of the sheet 7 is not brought into direct contact with the part 6, a reverse adherence or readherence of a dirt adhered to the sheet 7 can be prevented, and a physical load of the head 5 can be reduced.