To enable thickening of a rim part/hub part and thinning of a rib part without conducting welding/cutting from a plate material and with low energy concerning a method and an apparatus for forming a stock for a rotary part from the plate material.

A disk shaped plate 10, while freeing the outer peripheral part to be thickened, is clamped from both sides with a clamp 12, the outer peripheral part 10-1 of the plate material is thrust in the inward radial direction by a thrust roller 18 under the state imparting rotary motion for the plate material 10 clamped, so as to cause fluidization in the width direction of the outer peripheral part of the plate material, thickening of the outer peripheral part of the plate material is conducted. Forming of the hub part is conducted with pierce-burring and subsequent press-thickening from both sides, in order to minimize thinning in pierce burring, a hub part is, in advance, subjected to shallow drawing opposite to a forming direction of the hub part. Thinning of the rib part is conducted through shear lateral sliding due to thrust to a taper roll.