NOVELTY - The method involves increasing quantity of other thermal medium supplied to portion which cools mixed gas from heat pump more than quantity of other thermal medium cooled by low temperature supplied to portion which cools mixed gas from storage tank. The quantity of other thermal medium cooled by low temperature supplied to portion which cools mixed gas from tank is increased more than quantity of another thermal medium supplied to portion which cools mixed gas from pump, when target temperature range is exceeded than measurement temperature.    USE - Pre-processing method of biomass used for manufacturing bioethanol.    ADVANTAGE - The mixed gas diffused from the ammonia comprising saccharification preprocessed material is efficiently cooled by the appropriate quantity of heat-of-cooling energy irrespective of quantity.    DETAILED DESCRIPTION - The method involves mixing lignocellulosic biomass made into batch type substrate with aqueous ammonia, and obtaining substrate mixture. The substrate mixture is heated to predetermined temperature. A lignin is made to dissociate from substrate, and ammonia comprising saccharification preprocessed material is obtained. An ammonia separation saccharification preprocessed material which diffused mixed gas of ammonia vapor and water vapor from ammonia comprising saccharification preprocessed material and from which ammonia separated is obtained. The mixed gas diffused from ammonia comprising saccharification preprocessed material is cooled and condensed. Other thermal medium is supplied to heat pump which heats one thermal medium which heats substrate mixture. Other thermal medium is cooled at low temperature rather than temperature at time of making major cycle path circulate through another thermal medium, by making bypass circulation path circulate through other thermal medium. The predetermined amount storage of other thermal medium cooled by low temperature is carried out previously at storage tank. The target temperature range and measurement temperature measured downstream from portion which cools mixed gas of major cycle path are compared. The said heat pump is binary system heat pump (20). The storage of other thermal medium is performed before process of obtaining ammonia comprising saccharification preprocessed material from process of obtaining substrate mixture.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view illustrating the pre-processing process of biomass.    Preprocessor (1)    Reaction container (2)    Control apparatus (6)    Binary system heat pump (20)    Low-temperature water pipe (48)