Abstract: Upon issuance of a check, predetermined mark data are added to data and letters indicating an amount of money so as to be converted into new data and letters indicating the amount of money. Further, the printing capacity of a preset printing area on the check is compared with the volume of printing data to be printed, and a printing font to be used is selected in accordance with a result of the comparison. A separate template on which a plurality of initial printing positions and codes for indicating the initial printing positions are indicated is superposed with the check, and the corresponding code is inputted so as to designate an initial printing position. With this arrangement, it is possible to provide a small-sized printer which can enhance the visibility of the content printed on the check, can prevent the letters indicating an amount of money on the check from being raised so as to enhance the trust in banking transaction, and can easily set an optimum printing position.