It is possible to compensate for waterproof with a simple structure, and to achieve a reduction in the number of parts and a reduction in the connecting operation time.There is a connecting member that connects a first member 100 to a second member 101, wherein the connecting member is a fastening screw 10, having a head 11 on one side thereof and having a threaded portion 12 on the other side thereof, which performs connecting by fastening, and a plurality of rows of annular grooves 13 are formed in a seat surface 11a of the head 11 around a shaft of the screw. In addition, the head side of the fastening screw 10 is provided with a neck having a larger diameter than the diameter of the threaded portion which is closely inserted into an insertion hole of the first member, and a plurality of rows of annular grooves 13 are formed on the outer circumference of the neck.