An acceleration sensor comprises a vibrating element 2 formed by arranging conductor films 26 and 29 on outer main surfaces of piezoelectric substrates 21 and 22 in a rectangular parallelepiped shape, and first supporting members 3a and 3b for holding a part of the vibrating element 2, the first supporting members 3a and 3b being composed of an elastic body, and a bending point of the vibrating element being positioned within a supporting region 91 held between the first supporting members 3a and 3b. This causes a region, which is distorted, in each of the piezoelectric substrates 21 and 22 to be enlarged. Therefore, the amount of charges to be generated is increased so that an output voltage is increased, which allows acceleration detection sensitivity to be further enhanced.