PURPOSE: To contrive to reduce the capacity of a current of the drive power source of a thermal stamp and simplify its circuit without sacrificing its recording speed by such an arrangement wherein the interval between electrodes of its numeral recorder is made narrower than that of its fixed recorder and recording is to be performed by time sharing system.

CONSTITUTION: While a drive circuit for recording fixed pattern 8 at a fixed recorder 2 applies a specified voltage to interdigital electrodes, a digit selection circuit 9 at a numeral recorder 3 selects interdigital electrodes 6aW6d in sequence at a fixed interval of time and is synchronization with that, it supplies recording data D1WD7 to segment drive circuits 11W17, and by this operation, interdigital electrodes 6aW6d are impressed with a voltage by such a pattern corresponding to recording data D1WD7. At this time, the interval between electrodes of electrodes 6aW6d is made narrower than that of electrode 4, therefore the amount of heat generated per unit time is large and the recording of the numeral recorder 3 is completed within recording time at the fixed recorder 2.