PURPOSE: To detect a variety of movements by a single sensor, by mounting a weight at a free end of a sensor element of a slender flat plate one end of which is fixed, and separating the center of gravity of the weight away from the element in a direction to cross the surface of the sensor element.

CONSTITUTION: A sensor element 1 of a long and narrow flat, plate is constituted of a piezoelectric element, a strain gauge, a semiconductor gauge or the like. One end of the sensor element 1 from which a lead wire 11 is drawn out is accommodated and fixed in a fixed frame 2 which is filled with an adhesive 20. A weight 3 is mounted at the other end of the element 1 via a mounting frame 4. The weight 3 is shifted in a direction to cross the surface of the element 1. The center of gravity of the weight 3 is positioned away from on an extension line of the cantilever element 1. Since the center of gravity of the weight 3 is at the position shifted from the element 1 not only when the element is moved in the X-direction, but when the element is moved in the Y-and Z- directions, the element 1 always warps, making it possible to obtain the detecting output of the movement in the X-, Y-, Z directions.