To obtain a metallic product having the fixed thickness and high strength and finished to the hard surface at a low cost by applying sliding, turning and swinging to a hammer side and a product forming table side, matching to the position of both sides and hammering.

A hammer arm 3 is supported to a supporting column 2 at the base end side so as to be swingable in the horizontal direction and slidable, and a hammer mechanism 4 can freely be swung on the base table 1 with the supporting column 2 as center. A swing means is mechanically connected with gear, belt, etc., by obtaining a driving source with a motor and is swingable by interposing bearing etc., and further, a sliding means is mechanically connected with gear, belt, etc., by obtaining a driving source with a motor and one side of recessed groove and the other side of recessed groove interpose the slidable rail etc. The hammer 6 is vertically moved with the hammer mechanism 4 and the surface of the metallic product W is hammered. The hammer 6 is provided with plural pieces and exchanged according to the dimension of the metallic product W, the forming position, the pattern for forming on the surface of the metallic product, etc.