PURPOSE: To ensure that the sequence of printed results is always recognized and serially print page numbers even when printing a series of data through a plurality of jobs, by providing a printer capable of automatically printing page numbers on printed papers.

CONSTITUTION: When a data-recognizing part 11 recognizes a command as one for starting automatic page printing, printing in an automatic page-printing mode is started. When a line-feeding command is present in inputted data (a), the part 11 outputs a counting signal to a counter 21 for the number of lines, then the counter 21 counts down, and when the counted value in the counter 21 reaches zero, the counter 21 outputs a page end signal. A page number counter 22 counts the page end signal, and outputs a counted value "1" to a page data generating circuit 23. A data-combining circuit 24 inhibits inputting of data from a data- converting part 12, and outputs a motor-driving signal to a printing part 14 to print the page number, followed by shifting the page.