PURPOSE: To increase the maximum flow for increasing a valve capacity and miniaturizing the whole valve device by preventing the smooth flow of fluid in the valve body from causing the pressure loss.

CONSTITUTION: A valve body 21 has first and second flow paths 27, 28 communicating respectively from side and below to the inner space almost perpendicularly thereto. Also, the inner space in the valve body has a cup-like plug 30 having both sides of side plates 32, 32 opposed to each other and disposed to open and close an opening 29 communicating to both flow paths 27, 28. This plug is formed such that the connection part of the inner space of the valve body and one flow path presents a nearly elbow-shaped configuration when the valve is opened.