Abstract: There is disclosed a method of cleaning a semiconductor wafer after lapping in the manufacture thereof comprising the steps of slicing a monocrystalline ingot into a semiconductor wafer, and chamfering, lapping, acid-etching, and then mirror-polishing the thus-obtained semiconductor wafer. The semiconductor wafer is cleaned in a strong-alkaline aqueous solution at a point of time after the lapping and before the acid-etching, such that the surface of the semiconductor wafer is dissolved in an amount in the range of 4-8 .mu.m. The cleaning method prevents generation of a protrusion on the outer circumferential end portion of the wafer in the subsequent acid-etching step.