PURPOSE: To simplify the structure by providing a control valve including a valve box body having an inlet portion, branch connecting pipe portion and cylindrical hole portion, cover body, a valve rod, and a flow switching valve for cutting off the passage of the existing fluid pipe, wherein the valve rod is mounted on the cover body, and the valve body closes an opening portion of the branch connecting pipe portion in retreat and opens the opening portion in advance.

CONSTITUTION: A control valve device S mounted to a piping P includes a valve box body 1, a cover body 4 fitted in an inlet portion 2 of the valve box body 1, and a flow switching valve 5 mounted on the cover body 4 in such a manner as to freely advance and retreat in the valve box body 1. The valve box body 1 is projectingly provided with a branch connecting pipe portion 3 near the inlet portion 2. The cover body 4 is fitted in the inlet portion 3 of the valve box body 1. and is sealed with a packing 26. The flow switching valve 5 is composed of a valve body 5A and a valve rod 5B. The water colliding with a rectangular valve portion 35 is made to flow out through a water flow port. The valve rod 5B is inserted into an insertion hole 30 of the cover body 4. As a result, it is possible to achieve miniaturization and reduce a cost.