PURPOSE: To attain enhancement of the transaction efficiency of business by providing classifying/totalizing function to a printer, by providing a data memory means, a control means of enabling the printing of desired data by key operation and an operation means of performing the operation of data at every classification to a printer.

CONSTITUTION: A special character is printed on a slip such as a check or a bill using magnetic ink after an order or data has been inputted from input means 10 by pressing a key and, at the same time, data such as money received or the amount of contribution is stored in a memory means 30 at every classification and the sum amount and other data are totalized by an operation means 40 to be stored in the memory means 30 along with the data. A total amount or a sum total amount at every classification or information desired to be printed along with the total amount can be also subjected to MICR printing by the key operation of the input means 10. Therefore, when the slip such as the check or the bill subjected to MICR printing processing in series is classified, the number of the slips at every classification or the total amount can be immediately recognized and the succeeding transaction of business is easily performed and processing efficiency can be enhanced.