To provide a method for generating steam from a black liquor of a digester plant in a chemical pulp mill.

A method for generating steam includes the steps of: (a) generating a black liquor by a digester system; (b) extracting 4 a first flow of the black liquor, and subject 6 the same to evaporation by using fresh steam as a heating medium to increase a dried solid concentration of the black liquor after subjected to the evaporation; (c) using steam 11 obtained by the evaporation for heating fiber materials of the digester; (d) generating flashed black liquor and flash steam by flashing 15 a second flow of the black liquor extracted from the digester to produce clean steam by introducing the flash steam to at least one kind of heat exchanger, preferably a reboiler 17 to indirectly heat exchange with a clean vaporizable liquid; (e) usign 2 the clean steam for steam treating chips; and (f) guiding 18 the flashed black liquor further to an evaporation step.