NOVELTY - The method involves heating biomass fine granule particle (11) filled in reaction container (2) for obtaining solid substance in an approximately dense state. The biomass fine granule particle is pressurized so that the pressurization portion (6) carries out up-and-down sliding of reaction container. The backing pressure of hydraulic cylinder (7) which drives the pressurization portion is detected. The pressurization portion is raised and the biomass fine granule portion is degassed, when the detected backing pressure is larger than preset tolerance range.    USE - Method for manufacturing bio-coke used as fossil fuel in iron manufacture industry and reducing agent in casting furnace or blast furnace and baking fuel in electric power generation.    ADVANTAGE - Since the pressurization portion is raised and the biomass fine granule portion is degassed, when the detected backing pressure is larger than preset tolerance range, the bio-coke can be manufactured efficiently in short time and the waste gas being included in the bio-coke can be avoided.    DETAILED DESCRIPTION - The raise time of pressurization portion is measured, if the time measured by the timer passes the predetermined setup time. The pressurization portion is dropped from upper portion of reaction container and the biomass fine granule portion is pressurized from the pressure range with the pressurization portion at low pressure after supplying the biomass fine granule portion into the reaction container. An INDEPENDENT CLAIM is included for bio-coke manufacturing apparatus which has a pressurization portion that pressurizes the biomass fine granule portion in the reaction container. A heating portion heats the biomass fine granule portion. A cooling portion cools the molded object for obtaining solid substance within the predetermined pressure range. A backing pressure detection unit detects the backing pressure of hydraulic cylinder which drives the pressurization portion. The control apparatus performs pressure control of pressurization portion. The control apparatus is provided with a timer that measures the raise time of pressurization portion. The electromagnetic control valve controls supply discharge of working fluid to the hydraulic cylinder. The electromagnetic valve and non-return valve is positioned at the working fluid channel between backing pressure chambers of hydraulic cylinder. The control unit carries out pressure control of biomass fine granule portion, when the heating unit is operated in initial pressure rating of the pressurization portion. The control is switched from the heating unit to cooling unit, when the heating unit is operated in other pressure rating of pressurization portion.    DESCRIPTION OF DRAWING(S) - The drawing shows an explanatory view explaining the operation of degassing process.    Reaction container (2)    Hopper (3)    Pressurization portion (6)    Bottom face cover portion (9)    Biomass fine granule particle (11)