To provide a defect inspecting method and defect inspection device for properly inspecting various defects in wiring formed in an electronic device.

A detection circuit (RC circuit) which can impress an AC voltage to a wiring 2 is constituted while regarding disconnection defects 4 of the wiring 2 as a capacitor. By impressing an AC voltage to the wiring 2, and irradiating a sample 1 with a laser light 5, the wiring 2 is partially heated. When the laser light 5 is irradiated to a defect of disconnection 4, the capacitance of the disconnection defect 4 varies, and the impedance of the detection circuit varies. This impedance change is detected from, for example, the variations in the current value flowing in the detection circuit or in the resonance frequency variation during the irradiation of the laser light 5, when impressing AC voltage with the resonance frequency. From the correspondence of the position on the sample 1 and the irradiated position of the laser light 5, when the variation has appeared, the position of the disconnection defect 4 can be specifically detected. By regarding a void defect as a capacitor, it also can be detected similarly.