Abstract: The invention proposes an improved method for the pre-treatment of a photoresist layer formed on a substrate surface prior to pattern-wise exposure of the photoresist layer to actinic rays, in which extraneous portions of the resist layer formed by overspreading of the photoresist solution as in the marginal zone of the patterning area and on the peripheral and back surfaces of the substrate, by dissolving away with a cleaning solution. In contrast to the conventional cleaning solutions consisting entirely or mainly of an organic solvent capable of dissolving the photoresist composition, the cleaning solution used in the inventive method is an aqueous alkaline solution containing a water-soluble alkaline compound dissolved in an aqueous medium consisting of water and a limited amount of a water-miscible organic solvent such as monohydric alcohols, alkyleneglycol monoalkyl ethers and aprotic solvents. The cleaning solution may optionally contain an anti-corrosion agent.