To simplify the equipment, to reduce the cost, and to form a dynamic pressure groove in a short time.

A rugged part inclined in the axial direction is formed on the outer circumferential surface of an annular expandable member which is elastically expandable. A filling space 7 filled with the working fluid is provided on the inner diameter side of the expandable member 6. After a sleeve stock 1 is fed on the outer circumferential surface of the expandable member 6, the oil in the filling space 7 is pressurized to expand the expandable member 6, and a formed part of the expandable member 6 is pressed against the inner diameter part of the sleeve stock 1 to form the dynamic pressure groove of the shape corresponding to a projected part of the formed part is formed in the inner diameter part. Then, the filling space 7 is decompressed, and the expandable member 6 is contracted, and the sleeve stock 1 is drawn out of the expandable member 6.