Connecting member of construction machine

A connecting member of a construction machine has an intermediate support member disposed between first and second support plates. The intermediate support member has a bottom plate formed with a draw-out hole for drawing out a casting mold and disposed facing the boom, and a cover plate continuous with the bottom plate and disposed facing the arm so as to cover the draw-out hole. A projection protruding in a draw-out direction of the casting mold is formed in at least a part of an edge facing the draw-out hole, in the bottom plate, the projection having an inner peripheral wall and an outer peripheral wall with respect to the draw-out hole.