The band attachment device (1) and the closed case (17) together form the housing of the wristwatch. The device (1) is a perforated construction, the central part (2) of which contains the closed case (17) and the side parts (3 and 4) of which provide the connection to each half of the band. The device (1) is made entirely of elongate elements of metal or plastic sections joined by welding or adhesive bonding and arranged in such a way as to form a rigid, lightweight lattice.