A connecting device includes two complementary coupling members (3, 4) secured respectively to the connecting ends of a wrist band (2a, 2b) and of the component to which it is attached. The coupling members (3a, 3b) are oriented transversely to the longitudinal direction of the wrist band (2a, 2b). One (3) of the coupling members is movable laterally between two end positions, a first position in which it is engaged with the other (4) of said coupling members, and a second position in which it is dissociated from said other coupling member (4). An elastic return force (5) tends to keep said coupling member (3) movable laterally between two end positions in said first position.