To suppress vibrations by speed variation of a belt without using a cushioning material.

In a belt element 200 having a body part 201 formed in a substantially trapezoidal shape, a neck part 202 extended from the center part of the body part 201 and a head part 204 which is connected to the neck part 202 and formed in a substantially triangular shape, a bending in a body part 207 of the head part 204 is made relatively large. By so doing, the body part 207 of the head part 204 on the belt compression side having a relatively large bending has a damping function. By moving forward and backward in the advancing direction and absorbing vibrations like a spring, vibrations by speed variation can be suppressed. The sheave having a relatively small bending is interposed between sheaves so that strength of the body part 201 can be secured. On the other hand, the body part 207 of the head part 204 having relatively larger bending is kept from contact with a sheave, which leads to a small influence on the strength of the whole belt element 200. Therefore, the strength of the whole belt element 200 can be secured.