A valve includes a valve seat having a hole configured as a flow path, a valve body configured to open/close the flow path due to relative movement with respect to the valve seat, an opening member having a first surface fixed to one of the valve seat and the valve body, a second surface configured to separate away and abut the other one of the valve seat and the valve body, a third surface which intersects the first and second surfaces, and an opening penetrating the first and second surfaces, a fixing member that fixes the first surface to the one of the valve seat and the valve body, and an inclined portion, which makes an interval between the one of the valve seat and the valve body and the first surface long in a direction from the opening to the third surface.