NOVELTY - Method for saccharifying lignocellulosic biomass, involves (a) performing pretreatment process by impregnating the lignocellulosic biomass with an aqueous alkali solution to obtain pre-treated mixture, subjecting the pre-treated mixture to solid-liquid separation for removing the aqueous alkali solution and subjecting separated product to heat treatment, and (b) subjecting product obtained in the step (a) to saccharification process for enzyme degradation of the lignocellulosic biomass to obtain saccharified liquid.    USE - The method is useful for saccharifying lignocellulosic biomass e.g. woody plant, timber, processed products, waste materials and construction waste material for obtaining sugars chosen from glucose, xylose and arabinose used in feed and fertilizer, and as raw material for fermentation production of chemical products chosen from ethanol, isobutanol, 2-propanol, lactic acid, succinic acid, acetic acid, 3-hydroxypropionic acid, pyruvic acid, citric acid, acrylic acid, itaconic acid, fumaric acid, amino acids, isoprene and 1,3-propanediol.    ADVANTAGE - The method is suitable for saccharification of lignocellulosic biomass containing high lignin content. The method reduces amounts of alkali and water used during the pretreatment process, reaction time of the saccharification process and load of degradation product removal produced during the pretreatment process, and improves yield of sugar and enzyme recovery, as enzyme adsorption onto the biomass residues is reduced hence usage amount and cost of the enzyme is also significantly reduced, thus the method is cost-effective. The method enables obtaining saccharified liquid having excellent fermentation characteristics. The by-products/residues generated after the completion of the saccharification method can be effectively utilized as biomass fuel for steam or electric power production.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for saccharified liquid obtained by the above-mentioned saccharification method, which comprises 2-20 %mass degraded products of the solubilized lignocellulosic biomass with respect to total sugar components in the saccharified liquid.