A portable display device, such as a contactless IC card, comprising, for example, cholesteric liquid crystal with a memory capability and having an improved mechanical durability. The display device has two opposed substrates (1) and display portion (liquid crystal) (2) interposed between the substrates (1). The display device further has a wall member (3) which is a wall structure holding the substrates at portions other than the display portion (2). The walls are perpendicular to the substrates (1), and the surfaces perpendicular to the walls are adhered to the substrates (1). The area of the surfaces adhered to the substrates (1) is larger than that of the surfaces of the display portion (2) opposing the substrates (1).