An electronic device has a case that is formed by combining first and second members respectively having first and second engaging portions formed along an outer circumferential portion thereof such that the first and second members make contact with each other. The electronic device includes a corner engaging member having a rib, an outer supporting member and an inner supporting member. The rib is formed at a corner portion of the first engaging portion such that the rib is curved along the corner portion. The outer supporting member is formed at a corner portion of the second engaging portion, which corresponds to the corner portion of the first engaging portion. The outer supporting member makes contact with an outer circumferential surface of the rib. The inner supporting member makes line-contact with an inner circumferential surface of the rib. The rib is inserted between the outer supporting member and the inner supporting member.