An electronic device has an opening in a case, a lid member that includes a first lid member having a pair of first engaging sections for putting a lid on the opening at its both ends, a second lid member that has a pair of second engaging sections engaging with the first engaging sections and slides on a main surface of the first lid member, and a projection disposed at an end of the sliding direction of the second lid member. The case has an engaging hole engaging with the projection disposed on the second lid member.