To provide an on-vehicle device where improvement in efficiency and cost reduction of arithmetic processing are achieved.

The on-vehicle device for detecting a vehicle behavior state in a vehicle comprises a position detecting means for detecting the current position of one's own vehicle, a calculating means for calculating a first value showing a behavior state (vehicle speed, yaw rate, or acceleration) based on the hysteresis of the one's own vehicle current position detected by the position detecting means, an output means (vehicle speed sensor, yaw rate sensor, or acceleration sensor) for detecting the behavior state of the one's own vehicle and outputting a second value showing the behavior state, and a determining means for determining a correction factor with respect to the second value output by the output means using the first value calculated by the calculating means.