To improve the operability of opening a door, by a construction wherein a projecting part for absorbing the displacement with time of an engagement part is provided on either of the sides of an opening part and a transmitting part being opposite to each other.

This opening-closing mechanism is so constructed that one end side of an opening lever 8 is pressed by an opening button 11 and that an engagement part 5a is pressed by the other end side of the lever. In this construction, the opening button is equipped with a plurality of legs 11a, 11b and 11c pressing the opening lever 8 and the lengths of the legs 11a, 11b and 11c are set to be larger sequentially from the side in proximity to the other end side of the opening lever 8.