Abstract: A liquid crystal cell (3), a circuit substrate (12) and a battery holder (10) are housed in a case body composed of an upper cover (8a) having a display window, a lower cover (8b) and a frame (9). A connector including a large number of signal terminals is connected to one end of the circuit substrate (12), and the circuit substrate is arranged on the liquid crystal cell (3) one above the other within the case body. The battery holder (10) is arranged in parallel to the circuit substrate (12).

Abstract: A card body 2 has two battery holding sections (13, 14) inside, and two battery holders (9, 10) each containing a battery are housed therein. The two housed battery holders (9, 10) engage locking portions (22a, 22b) of a stopper (11), thereby setting them unremovable. When the stopper (11) is slid toward one battery holding section (14), the battery holder (10) therein is still kept unremovable, while the other battery holder (9) can be made removable. Thus, even during battery change, at least one battery always remains in the card body to keep supplying a backup voltage to a volatile memory.