An electromechanical microsystem including an electromechanical transducer, a deformable diaphragm and a cavity hermetically containing a deformable medium keeping a constant volume under the action of an external pressure change. The deformable diaphragm forms a wall of the cavity and has at least one free area so as to be elastically deformed. The electromechanical transducer is configured so that its movement depends on the change in the external pressure, and vice versa. The free area cooperates with an external member so that its deformation induces, or is induced by, a movement of the external member. Thus, the electromechanical microsystem is adapted to displace the external member or to detect a movement of this member, the electromechanical microsystem includes at least one pin, configured to bear on a peripheral portion of the free area so that a deformation of the free rea causes an inclination of the pin.