An embodiment provides a method for measuring particles on a wafer surface, the method including: disposing and rotating a wafer on a stage; irradiating a laser in a first region of a center of a surface of the rotating wafer, a second region between the first region and a third region, and the third region at an edge thereof; and measuring a laser reflected from the first to third regions of the wafer, wherein a second output of the laser irradiated in the second region is larger than a first output of the laser irradiated in the first region and a third output of the laser irradiated in the third region is larger than the second output of the laser irradiated in the second region.