To solve the problem that a cost increase is brought about due to another process such as hot stamping or reflecting plate attachment taken in the case where a reflecting plate or the like for misdetection prevention is set on a tray to be countermeasures against user's misinsertion of the tray as in conventional machines, the problem that printing starting is delayed due to the fact that misinsertion is not noticed until the action of position detection of the tray, and the like problem.

Ribs are set on a transfer tray top face at positions prevented from entering a printer body during the printing action. The transfer tray is prevented from being inserted reversely, without being accompanied with the cost increase.