PURPOSE: To easily form a tapered work and release it from a die in a rotary cam type forming device.

CONSTITUTION: In the forming device PM for metal plates in which a rotary cam 30 which is rotatable around a longitudinal axis Lc is provided on the side of a lower die 11, on the other hand, a slide cam which is advanced to the rotary cam side with the lowering motion of the side of an upper die 1 is provided on the side of an upper die and the work W is formed into a prescribed shape between the forming part of the rotary cam and the bend punch of the slide cam in a prescribed rotational position of the rotary cam, a moving mechanism 40 with which the rotary cam is moved in the axial direction is provided. The moving mechanism 40 is composed of a screw mechanism 41 which is provided on one end side in the axial direction of the rotary cam, a screw member 42 which is screwed onto the screw mechanism 41 and a driving means 51 for revolving the screw member 41.