To enable interruptions of a plurality of accounting procedures in the accounting procedures of a POS terminal device, and to efficiently process the interruptions and the restarts.

In the POS terminal device, when interrupting input by an input part 1 in some accumulating procedure, data on an interrupted processing object are temporarily stored in a data storage part 2d. If the plurality of interrupted processing objects are targeted, all the data are stored in the data storage part 2d. When restarting the interrupted accounting procedure after the storage, the restart is indicated from the input part 1, and the data is read from the data storage part 2d and is displayed on split screens in a display part 3. Items capable of being processed on the split screens wherein display items are limited are processed on the split screens. If the processing on the split screens is not possible, a normal screen (one screen) on which all the items are displayed is displayed, and the accounting procedure is restarted. The accounting procedure is executed according to a control program of a memory part 2.