An electronic device comprising: a case section including an opening (210,211,920); and a lid member (140,150,700) for opening and closing the opening (210,211,920), the lid member (140, 150, 700) including: a first lid member (310,710,810) having a pair of first engaging sections at both ends of the first lid member (310,710,810); a second lid member (320,720,820) 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 (310,710,810); and a projection (380a, 780a, 830a) disposed on the second lid member (320, 720, 820) at an end in the sliding direction of the second lid member (320,720,820), the case section having an engaging hole (250a,940a) engaging with the projection (380a,780a,830a), and an end of the first lid member (310, 710,810) on a side opposite to the end of the second lid member (329,720,820) having the projection (380a, 780a, 830a) being hingingly attached to the case section; characterized in that an elastic member is directly mounted to a first side of the first lid member (310,710,810); and the second lid member (320,720,820) is configured for closing the opening (210, 211, 220) by sliding on a second side of the first lid member (310,710,810) which is opposite to the first side in a direction which is perpendicular to the direction between the ends having the first engaging sections of the first lid member (310,710,810) and away from the end of the first lid member (310,710,810) which is attached to the case section. a case section including an opening (210,211,920); and a lid member (140,150,700) for opening and closing the opening (210,211,920), the lid member (140, 150, 700) including: a first lid member (310,710,810) having a pair of first engaging sections at both ends of the first lid member (310,710,810); a second lid member (320,720,820) 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 (310,710,810); and a projection (380a, 780a, 830a) disposed on the second lid member (320, 720, 820) at an end in the sliding direction of the second lid member (320,720,820), the case section having an engaging hole (250a,940a) engaging with the projection (380a,780a,830a), and an end of the first lid member (310, 710,810) on a side opposite to the end of the second lid member (329,720,820) having the projection (380a, 780a, 830a) being hingingly attached to the case section; characterized in that an elastic member is directly mounted to a first side of the first lid member (310,710,810); and the second lid member (320,720,820) is configured for closing the opening (210, 211, 220) by sliding on a second side of the first lid member (310,710,810) which is opposite to the first side in a direction which is perpendicular to the direction between the ends having the first engaging sections of the first lid member (310,710,810) and away from the end of the first lid member (310,710,810) which is attached to the case section. a first lid member (310,710,810) having a pair of first engaging sections at both ends of the first lid member (310,710,810); a second lid member (320,720,820) 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 (310,710,810); and a projection (380a, 780a, 830a) disposed on the second lid member (320, 720, 820) at an end in the sliding direction of the second lid member (320,720,820), the case section having an engaging hole (250a,940a) engaging with the projection (380a,780a,830a), and an end of the first lid member (310, 710,810) on a side opposite to the end of the second lid member (329,720,820) having the projection (380a, 780a, 830a) being hingingly attached to the case section; characterized in that an elastic member is directly mounted to a first side of the first lid member (310,710,810); and the second lid member (320,720,820) is configured for closing the opening (210, 211, 220) by sliding on a second side of the first lid member (310,710,810) which is opposite to the first side in a direction which is perpendicular to the direction between the ends having the first engaging sections of the first lid member (310,710,810) and away from the end of the first lid member (310,710,810) which is attached to the case section.