A stencil printing apparatus which suppresses master consumption by switching between simplex printing using a simplex master and single-step duplex printing using a duplex master automatically in accordance with master information and sheet information comprises a printing drum and pressing means, and can be made to switch between duplex printing, in which a rear surface printing step is performed after a front surface printing step, and simplex printing by wrapping a duplex master formed with a first engraved image and a second engraved image around the printing drum during duplex printing, and wrapping a simplex master formed with a third engraved image for simplex printing around the printing drum during simplex printing. Master identification information, indicating whether the master was engraved with duplex printing images or a simplex printing image during engraving, is stored in a storage unit in association with plate cylinder identification information, and either a duplex printing mode or a simplex printing mode is selected on the basis of plate cylinder identification information obtained anew when an operation command or a plate cylinder attachment/detachment command is input into the apparatus, and the master identification information stored in the storage unit.