Abstract: In a position sensor manufacturing method for manufacturing a modulation-demodulation type position detecting system provided with a signal processing circuit including an excitation signal generating section for generating an excitation signal to be supplied to a position detecting section and a synchronous detection section for demodulating a sensor output signal from the position detecting section by synchronous detection, a sensor output measuring unit is used to measure the sensor output signal, and an excitation signal to be generated by a D/A convertor of the excitation signal generating section is corrected based on data obtained from a switching signal used to sample the sensor output signal and the sensor output measuring unit to correct a synchronous deviation between the switching signal and the sensor output signal.