The present invention relates to a defect inspection apparatus based on the fact that contrasts of a grain and a void of a semiconductor copper interconnect in a scanning electron microscope are changed depending on electron beam irradiation accelerating voltages. A charged particle beam apparatus of the present invention irradiates the same portion of a specimen with electron beams at a plurality of accelerating voltages, and differentiates a grain (65, 66) from a void (67) on the basis of a contrast change amount of the same portion in a plurality of images (61, 62) acquired so as to respectively correspond to the plurality of accelerating voltages. Consequently, it is possible to automatically detect a grain and a void in a differentiation manner at a high speed without destructing a specimen.