A mounting structure of a ball grid array type IC includes resin guide ribs provided on opposite sides of a body portion of the ball grid array type IC, engaging pawls formed at distal ends of the guide ribs so as to be locked into locking holes of a board, springs in which the guide ribs are inserted respectively, and height adjusting ribs provided at places slightly inwardly distant from the guide ribs respectively so as to protrude from the body portion. The springs prevent the ball grid array type IC from being strongly pressed against the board when the ball grid array type IC is mounted on the board. The height adjusting ribs adjust the ball grid array type IC to a predetermined height relative to the board.