There is disclosed a method for inspecting a physical feature on a surface of a manufactured article. First, a sensor is provided adjacent to the article. Then, the surface of the article is sensed by the sensor while causing one of the sensor and the article to rotate about an axis perpendicular to the surface of the article, to thereby obtain a signal which has peaks corresponding to the physical feature on the surface of the article. Subsequently the signal is processed and the processed signal is analyzed based on the number of the peaks, to thereby obtain information as to the physical feature on the surface of the article. An inspection apparatus suitable for practicing the above-mentioned method is also disclosed.