The fuel cutoff valve has a connection conduit that connects the connection hole to the approximately round shaped cross section tube passage. With the connection conduit, the connection hole and the flow path area are almost the same, and this comprises a curved passage part that makes the rising gas flow from the connection hole face in the horizontal direction, and a connection passage part that leads the gas flow from the curved passage part to the connection passage part. The fluid guide member that constitutes the curved passage part is a passage that has an inclined face that makes the rising gas flow that flows out from the connection hole face in the horizontal direction, and a passage upper surface formed from a flat surface continuous from the upper edge of the inclined face and arranged above the connection hole. The connection passage part is formed such that the cross section shape of the passage upper surface gradually faces the round shaped cross section of the tube passage.