A device for inspecting for minute flaws upon the outer surface of journal or pin portions of a crank shaft comprises a main device 12 and a control device 14. The main device 12 brings a gauge head 56, which can freely move forwards and backwards along a Y axis direction, into contact with an inspection region 16A of the the crank shaft 16 while rotating the crank shaft 16 around a rotational axis 16C, measures the surface position of the inspection region 16A for each of rotational angles, and obtains surface portion waveform data corresponding to rotational angle. The gauge head 56 has an oscillation function, and always contacts against the inspection region 16A during rotation. The control device 14 extracts high frequency waveform components from the obtained waveform data, and detects flaws on the inspection region based on the high frequency waveform components.