An apparatus and method of detecting a wafer edge using a laser scanner, and a semiconductor transfer device are provided. The apparatus for detecting a wafer edge using a laser scanner includes a laser scanner disposed on a rear side of a mounted wafer and radiating a laser to a portion of an edge of the wafer, and a detection unit receiving an image acquired by the laser scanner and detecting the wafer edge in the image. The detection unit determines whether each wafer is present or aligned according to wafer edges detected in a plurality of wafer areas in the image.