To provide a three-axis acceleration sensor that reduces costs, trouble, and faults and continuously detects a vibration constituent in a fixed direction even if changing the orientation of retention, and to provide a pedometer for continuously detecting a vibration constituent in the vertical direction by walking even if changing the orientation of retention.

A film-like piezoelectric element 2 (a detection section) is bonded to a side section 11b of a coil spring 11 (a flexible elastic body), and one end 11a of the coil spring is fixed to an installation section (the inside of the case of the pedometer). The coil spring 11 is deformed by receiving the vibration in the vertical direction by the walking even if the orientation of the installation section (the inside of the case of the pedometer) is changed to either direction, the coil spring 11 is deformed, and the film-like piezoelectric element 2 is deformed in accordance with the deformation of the coil spring 11 for outputting.