WEAR-CONDITION-SENSING DEVICE

A wear-condition-sensing device includes an element configured to generate voltage based on deformation of a tread portion during tire rotation, a voltage detection unit configured to detect the voltage generated by the element, a storage area configured to store waveform data over time of the voltage detected by the voltage detection unit, a calculation unit configured to calculate an index value of voltage change based on the waveform data stored in the storage area, and a determination unit configured to determine a progress condition of wear of the tread portion by comparing the index value calculated by the calculation unit with reference information.