Abstract: A thin-film structural body formed by using a semiconductor processing technique and a manufacturing method thereof, and particularly a thin-film structural body constituting a semiconductor acceleration sensor and a manufacturing method thereof. The thin-film structural body allows the thin-film member to be easily stress-controlled, and easily makes the film-thickness of the thin-film member thicker. The thin-film member forms a mass body and, beams and fixed electrodes of the semiconductor acceleration sensor are constituted by a plurality of doped polysilicon thin-films that are laminated by performing a step of film deposition of polysilicon while, for example, phosphorous is being doped as impurities plural times.

Abstract: A golf club head is formed of an alloy steel which comprises at most 0.2 wt. % of C, 0.05-1.0 wt. % of Si, at most 0.5 wt. % of Mn, 3.0-8.0 wt. % of Ni, 10.0-20.0 wt. % of Cr, 3.0-8.0 wt. % of Mo and 10.0-20.0 wt. % of Co, the remainder being substantially Fe, and has a metallic texture composed principally of martensite.

Abstract: A golf club head is formed of an alloy steel which comprises at most 0.2 wt. % of C, 0.05-1.0 wt. % of Si, at most 0.5 wt. % of Mn, 3.0-8.0 wt. % of Ni, 10.0-20.0 wt. % of Cr, 3.0-8.0 wt. % of Mo and 10.0-20.0 wt. % of Co, the remainder being substantially Fe, and has a metallic texture composed principally of martensite.