Abstract: In a rewritable card read/write apparatus including a printing thermal head (11) for printing data thermally and a transporting mechanism for feeding a rewritable card (19) forwardly and backwardly so that the rewritable card (19) can pass by the thermal head (11), a method which allows the printed data to be erased within a short time with the thermal head (11) itself. A columnwise printed data erasing range (18) of a printed data area is designated for the card (19) inserted into the apparatus. The thermal head (11) is electrically energized successively at least in two serial cycles by changing over electric energy level at least from a first electric energy level in a first cycle to a second electric energy level in a second cycle.