To provide an acceleration sensor capable of detecting an acceleration from various directions, and a pedometer using the sensor.

This acceleration sensor 10 is provided with a base member 1 curved along one plane, a piezoelectric element 2 provided on the base member 1 to be curved together with the base member 1, and a dead weight part 3 provided in one end part 1a of the base member 1. The piezoelectric element 2 and the base member 1 are curved into a circular arc shape. The acceleration sensor 10 is provided in the one end part 1a provided with the dead weight part 3 and the other end part 1b, and provided further with a support member 7 fixed to the base plate.