PURPOSE: To provide efficient printing method eliminating wasteful waiting time for printing, and to prevent an unprintable atate from occurring by a method wherein the number of bands in a buffer can be changed automatically, according to conditions of a page on which printing is made, to its maximum wherein expansion into page data is possible.

CONSTITUTION: The title apparatus is constructed of a memory B4 that produces display lists for each bands in the maximum number out of image data for one page and stores the produced lists, a memory C5 (buffer for one page) to be uses as a band for which the number of bands is variable, an error detector 7 and a CPU 6. In the case where an error is detected with the error detector 7 during the process of expansion from the display list to the buffer, an image formation device 9 and the buffer are reset and change is made to the band buffer method with the number of bands that is smaller by one than before.