An accelerated speed sensor (1A) having a high voltage sensitivity and capable of preventing reduction of polarization due to pyroelectric effect, comprises a piezoelectric element (2) and support members (10, 11) for supporting the piezoelectric element at both longitudinal ends thereof, the piezoelectric element is laminated with three piezoelectric layers (2a, 2b, 2c), each of the two outer piezoelectric layers (2a, 2c) are longitudinally divided into four units (1)-(4), (5)-(8), respectively, when being applied accelerated speeds. Interlayer electrodes (3, 4) and main surface electrodes (5a, 5b, 6a, 6b) are provided on the piezoelectric element (2) so that two cells (1, 2, 5, 6) on one side of the piezoelectric element and two cells (3, 4, 7, 8) on the other side are connected respectively, and the parallel-connected two sets of cells on the two sides are connected in series. The electrodes (5a, 6a), (5b, 6b) induced to different ends of the piezoelectric element (2) are connected with each other.