A positioning apparatus has a pilot holder having a hold face, a positioning pin having a tapered tip and supported by the pilot holder so that the tapered tip protrudes from the hold face of the pilot holder, a pad having a pad face that opposes the hold face of the pilot holder, and a movable member having a stop face that opposes the positioning pin and a relief hole for avoiding the tapered tip of the positioning pin from hitting the stop face, the movable member resiliently supported on the pad. The pilot holder and the pad in which the thin plate material is set between the hold face and the pad face relatively move to insert the tapered tip of the positioning pin into the positioning hole of the thin plate material. The stop face is flush with or protruding from the pad face of the pad.