In a printing apparatus, individual positional data for positions of four object marks provided on a plurality of FPCs held on a conveyance tray are acquired by a mark position acquisition section based on an image acquired by an image acquisition unit. In a displaced mark specifying section, relative positional relations of four object marks are determined, and compared with a reference positional relation, by which a displaced object mark is specified. Then, in a reference position determining section, a reference position for a plurality of FPCs on a conveyance tray is determined based on a plurality of object marks resulting from excluding the displaced object mark out of the four object marks. Thus, a reference position in execution of printing in a printing unit can be determined with high precision.