A non-destructive inspection apparatus includes a light source generating light, an optical coupler which divides the light, irradiates the divided light to a reference part and a sample part, generates coherent light, and transmits the coherent light to a detecting part, the reference part which phase-scans the irradiated light and reflects the light, the sample part which irradiates the light incident from the optical coupler to a display panel, and scans and reflects the light reflected from the display panel, the detecting part which obtains an image signal of the display panel from the coherent light, a transferring part which moves a position of the sample part, and the control part which generates an image of the display panel based on the image signal of the display panel transmitted from the detecting part and detects a foreign substance, and controls movement of the transferring part.