NOVELTY - Treating lignocellulosic biomass, comprises: (a) a pretreatment step of obtaining pretreated lignocellulosic biomass in a first reactor; (b) a first saccharification step of transferring the pretreated biomass from the first to a second reactor, followed by adding a first saccharifying enzyme and saccharifying the pretreated biomass with stirring; and (c) a second saccharification step of transferring the first saccharification product from the second to a third reactor, followed by adding a second saccharifying enzyme and saccharifying the first saccharification product.    USE - The method is useful for treating lignocellulosic biomass by saccharifying lignocellulosic biomass pretreated by dissociation of lignin or by swelling to obtain a saccharified solution (claimed), where the lignocellulosic biomass includes wood, rice straw, wheat straw, bagasse, bamboo, corn stalks, leaves, cobs, pulp, and wastes resulting from it e.g. waste paper.    ADVANTAGE - The method is capable of energy-efficiently treating lignocellulosic biomass in an economical manner. The saccharification product has improved flowability thus easily transportable.    DETAILED DESCRIPTION - Treating lignocellulosic biomass by saccharifying lignocellulosic biomass pretreated by dissociation of lignin or by swelling to obtain a saccharified solution, comprises: (a) a pretreatment step of obtaining lignocellulosic biomass pretreated by dissociation of lignin or by swelling, in a first reactor; (b) a first saccharification step of transferring the pretreated lignocellulosic biomass from the first reactor to a second reactor, adding a first saccharifying enzyme to the pretreated lignocellulosic biomass in the second reactor, and saccharifying the pretreated lignocellulosic biomass with stirring using a stirring unit to obtain a first saccharification product having flowability capable of being transported; and (c) a second saccharification step of transferring the first saccharification product from the second reactor to a third reactor, adding a second saccharifying enzyme to the first saccharification product in the third reactor, and saccharifying the first saccharification product to obtain a saccharified solution as a second saccharification product, where, after a power required for the stirring in the stirring unit gradually decreases and the rate of change of the power versus stirring time falls below a predetermined value, the first saccharification product is transported under non-air-contact conditions from the second reactor to the third reactor.