VALVE MEMBER AND EVAPORATIVE FUEL PROCESSING SYSTEM

A bottom wall portion of a valve member has an annular convex portion projecting from a bottom surface toward a valve seat. A rubber seal member has a flat plate portion in contact with the bottom wall portion, and an annular lip portion formed to project toward the valve seat at a position corresponding to the convex portion in the flat plate portion so as to abut on the valve seat at the time of valve closing. A projecting tip of the lip portion forms an arc-shaped part in the axial cross section of the valve member. A projecting tip of the convex portion forms an arc-shaped part having a curvature radius larger than a curvature radius of the arc-shaped part of the lip portion in the axial cross section of the valve member.