BODY MOVEMENT DETECTION SENSOR

The invention provides a body movement detection sensor using a piezoelectric film and having high detection accuracy and moreover, a structure capable of miniaturization. A body movement detection sensor provided with a sensor unit comprising a piezoelectric film, a right belt member extending from the right side of the sensor unit, a left belt member extending from the left side of the sensor unit, and an engagement member for engaging with an open end part of the right belt member and an open end part of the left belt member, wherein the piezoelectric film indicates a piezoelectric effect in the lengthwise direction, the right belt member and the left belt member have substantially no elasticity, an elastic sheet directly or indirectly connected to the right belt member and the left belt member is further provided, the piezoelectric film and the elastic sheet are arranged with substantially no irregularities when viewed from a side view, the elastic sheet has a maximum amount of expansion greater than the