To provide a cold wall type variable orifice valve which materializes a simple structure and cost reduction.

A tapered cone 23 whose diameter is reduced from the upstream direction to the downstream direction, is arranged in a valve body 22. The upstream side end of the tapered cone 23 is fixed onto the valve body 22. The downstream side end of the tapered cone 23 is fixed onto an orifice 24. Castable lining 25 is applied to the inside surfaces of the valve body 22 and the tapered cone 23.