Abstract: An angular sensor (10) is provided in a mobile body. A first setter (14) performs determination regarding the standstill state on the basis of whether or not the variation width of the angular speed is less than or equal to a predetermined value. A standstill determiner (20) determines whether or not the standstill state has continued beyond a determination time. An n?i sum-total averaging unit (34) calculates a sum-total average of (n?i) number of pieces of data obtained by excluding, from n number of pieces of data input during a period determined as a continuation of the standstill state, i number of pieces of data that are output immediately before the end timing of the period, and determines it as a zero-point offset. A zero-point corrector (36) performs the zero-point correction of the output value of the angular speed sensor (10), and outputs the corrected value to an output unit (28).