WASTE GATE VALVE DEVICE

A waste gate valve device in which a waste gate valve 100 is fully closed when a valve body of the waste gate valve 100 moves from an exhaust outlet passage 18s side toward an exhaust bypass passage 5 side and touches a seat face 12a of a valve seat part 12, wherein the valve body of the waste gate valve is provided with a protrusion 2 of a prescribed height on a touching side where the valve body of the waste gate valve touches the seat face 12a, the protrusion being configured so as to reduce an exhaust gas passage area of the exhaust gas.