Abstract: A semiconductor wafer has a pair of opposed major faces separated by a peripheral edge face. The peripheral edge face of the wafer is etched by one or more etching rollers which are brought into pressure contact with the wafer edge face under suitable contact pressure. The etching rollers and the wafer are rotated while in pressure contact, and an etching liquid is supplied to the rollers and transferred to the wafer during the rotation to effect etching of the edge face of the wafer. A washing roller applies a washing liquid, such as pure water, onto the wafer edge face to wash the same. Harmful gas vapors evolved during etching are prevented from contacting the wafer surfaces by blowing a pressurized gas, such as nitrogen gas, along the wafer surfaces toward the wafer periphery.