PURPOSE: To position a work in its specified position and posture by a device having simple structure without newly setting any specified conveyance reference to a work when plural works approximately in a similar shape are conveyed.

CONSTITUTION: A positioning device 20 having a holding member engaged with the existing shaft hole 10a of a work 10 is provided, and a posture deciding device 30 having a press member 31 by which one side of the work 10 is pressed and a stopper member 41 making contact with the other side of the work 10 is provided. By engaging the holding member with the shaft hole 10a from below, centering is rotatably made in a reference position on the work 10. One side of the work 10 is pressed by means of the press member 31 and rotation of the work 10 is stopped selectively in a plurality of stop position by means of the movable stopper member 41. Plural kinds of works 10 and 10' approximately in a similar shape are positioned in a specified position and posture.