An apparatus and a method are provided for accurately analyzing and evaluating a degree of contamination on a chamfered part without mixing impurities from parts other than the chamfered part into chemicals. At a position in which, on a front plane flat part of a semiconductor wafer, a boundary region bordering the chamfered part can come into contact with the chemicals, a radius direction position of the chemicals (a distance between a chemicals center and a wafer center) is determined, scanning is performed in a circumference direction, and the chemicals including impurities are collected. Then, at a position that can be brought into contact with the both chamfered part of the semiconductor wafer and the boundary region, a radius direction position of the chemicals is determined, scanning is performed in the circumference direction and the chemicals including impurities are collected. A liquid drop holder is, for instance, relatively rotated in the circumference direction from a desired start point on the circumference of the semiconductor wafer to a finish point.