A position sensor includes a detector, an oscillation circuit, a signal processing circuit, and a resonance circuit having a detection coil and a capacitor. The oscillation circuit forms a negative feedback loop from: an amplitude detection circuit that detects an amplitude of an oscillation signal outputted from the resonance circuit; an integrating circuit that outputs a signal corresponding to a difference between a predetermined reference voltage and the amplitude of the oscillation signal; a negative conductance control circuit that, based on the output of the integrating circuit, controls the negative conductance of the oscillation circuit such that the amplitude of the oscillation signal is equals to the predetermined reference voltage; and an operational amplifier that adjusts such that the oscillation voltage of the resonance circuit is equal to the applied voltage of the negative conductance control circuit.