PURPOSE: To perform a termination of a job (a printing request unit) being presently printed.

CONSTITUTION: Data with the addition of data for starting/completing a job transmitted from a printer driver 1.2 of a host device is received by a reception buffer 1.3. A job termination instruction to data stored on the reception buffer and data of a job under reception is inputted from an input part 1.6. In this manner, if data of a present job is all stored on the buffer 1.3, only the data of the present job is read, and the processing is continued from data of a next job. If data of a present job is under reception, the data on the reception buffer 1.3 is all read, data further transmitted from the host device and written on the reception buffer 1.3 are sequentially read, and the processing is continued from data of a next job.