To simplify a control mechanism to control opening and closing of apparatus consisting of two apparatus parts like a portable telephone.

In an apparatus like a portable telephone having one apparatus part being relative movement possible like a basement or a keyboard part (a lower shell) and a display part (an upper shell), both apparatus parts can mutually have a first and a second stable terminal position, a control mechanism is provided, both apparatus parts are pushed away from an arbitrary intermediate position to the one or the other terminal position. To obtain an especially simple intermediate control mechanism, a spring member is formed as a long cylindrical or a flat bending spring and held by the first apparatus part of the two apparatus parts. A control member is at least indirectly transmission-coupled to a second apparatus part, and the spring member is flagged and suitably tensed according to movement.