PURPOSE: To provide a positioning device with high efficiency, which can grasp, position and transport a sheet material in continuous operations by holding the sheet material, with the end edge of the sheet material brought into contact with a stopper for regulating the lateral and longitudinal positions of the material.

CONSTITUTION: When a sheet material 1 is carried in on a table 4, and detected by a detection switch 5, a cylinder 11 is expanded, so that a slider 15 is moved in C-direction along a closed loop 18 forming the contour of a window of a guide plate 13 toward a stopper 7 for regulating the lateral position of the sheet material 1 to be brought into contact with the stopper 7. The end edge of the material 1 on the opposite side to the stopper 7 pushes a finger support member 22, so that a finger 26 is closed through a link 25 to hold the sheet material. Subsequently, when a guide member 17 is driven in G-direction along the closed loop 18, the edge of the material 1 is disengaged from the support member 22, so that the support member is returned to the start point, leaving the material as it is to be on standby for the next process.