To operate a valve element with high speed, improve controllability of the valve element while improving resolution in minimum control, widely control pressure in an exhaust system of a semiconductor manufacturing device, and hold valve thrust at the time of the power failure.

A valve element 14 for opening or closing a hole 11 of a valve seat 10 is provided with an opening/closing part 15 and a needle part 16. The valve element 14 is sine curve-operated by a cross slider crank mechanism composed of a slider 42 and an eccentric cam 54, and the like by driving of a stepping motor 66. The valve element 14 is operated by the cross slider crank mechanism, and thereby, it is operated with high speed at an intermediate part, and it is operated in the vicinity of the summit of the sine curve. The valve element 14 is pressed to the valve seat 10 at a bottom dead center of the eccentric cam 54, and fastening reaction of the valve seat 10 is set so as to prevent rotation of the eccentric cam 54 from converting.