A non-contact AC voltage measurement device 100 applied to a conductor 12 of an electric wire 16, the device 100 being characterized in that a first electrode 32 is provided outside the electric wire 16, whereby a coupling capacitance 34 is formed between the conductor 12 and the first electrode 32, a parallel circuit 38 having a capacitor 40 and an opening/closing means 50 connected in parallel to the capacitor 40 is provided, the parallel circuit is connected in series to the coupling capacitance, and a first current I1 which flows through the parallel circuit 38 when the opening/closing means 50 of the parallel circuit 38 is closed and a second current I2 which flows through the parallel circuit 38 when the opening/closing means 50 is open are measured for the purpose of measuring the AC voltage 8 applied to the conductor 12.