PURPOSE: To enable printing to be carried out by taking an emulation mode which users intend by higher probability by a method wherein when there are a plurality of candidates for emulation, another part of a data stored in a receiving buffer is also taken as an object for judgement to advance processing.

CONSTITUTION: In a printer having a plurality of emulation modes 7a-7c, a storing means 4 stores a received printing data, and an analysis means 5 analyzes a data in a specific region among the stored receiving data and selects a conformed emulation mode among a plurality of the emulation modes. Further, a control means, when one emulation mode can not be specified by the analysis means 5, controls so as to add a data excepting at least the data in the abovementioned specific region to an analytical object of the analysis means. Consequently, printing can be performed by taking the emulation mode which users intend by higher probability.