Disclosed herein is a method of dividing a wafer including an exposed area incising step of lowering a cutting blade to a preset lowered position for fully severing the wafer to cause the cutting blade to incise an exposed area of a wafer unit, an image capturing step of capturing an image of the exposed area which the cutting blade has incised in the exposed area incising step, with image capturing means, a determining step of determining whether or not it is possible to fully sever the wafer on the basis of the captured image in the image capturing step, and an adjusting step of increasing a distance by which to lower the cutting blade if it is determined that it is impossible to fully sever the wafer in the determining step.