To enhance productivity and sensing precision, in a pedometer constituted to sense vertical vibration by each step so as to display total number of frequencies as the number of steps.

A sensor is provided in a case 12 to collide with a collision face of the case 12 in response to vertical aceleration in each step, that is, a piezoelectric sensor 13 is provided, in which an output voltage is increased by collision compared with that before the collision. An operation amplifier 14 for amplifying the output voltage of the piezoelectric sensor 13 upto a prescribed level to be output, and a computor 16 for superposing the output voltage before the collision and the output voltage at the time of the collision of the amplifier 14 to compute the number of collisions based on superposed wave forms are arranged inside the case 12, and an output of the computor 16 is input to a liquid crystal panel device 18 attached to one side wall of the case 12 to display the number of collisions as the number of steps.