NOVELTY - The method involves performing thermal decomposition of biomass feedstock, and generating pyrolysis gas. The tars are collected from the pyrolysis gas immediately after decomposition process.    USE - Manufacturing method of liquid fuel for boiler, diesel engine, etc., using biomass material such as rice straw, timber, woody fiber material, palm waste, maize core, rubber, used paper, waste materials, etc.    ADVANTAGE - High quality fuel oils are obtained depending upon the kind of biomass feedstock. Clogging of piping due to accumulation of non-volatile component is prevented.    DETAILED DESCRIPTION - The pyrolysis gas is discharged to cylindrical structure (11) installed in vertical direction. The liquid tar is collected using polar solvent supplied in collection tank (16) installed in lower end of structure. The tar and oil component are collected from the pyrolysis gas during liquid phase state while discharging the gas through the blow-in pipe. An INDEPENDENT CLAIM is included for manufacturing apparatus of liquid fuel using biomass material, which includes gravity-type separation apparatus (10) that is connected to a thermal decomposition reactor for thermal decomposition of biomass feedstock. The cylindrical structure is cooled while cooling jacket (12) is installed in the outer peripheral portion, and when pyrolysis gas is discharged in downward direction. The collection tank is installed in the lower end of structure, to collect the liquid when gaseous phase of pyrolysis gas is changed to liquid phase. The inner wall temperature of cylindrical structure is controlled to the condensation temperature of tar. A burner (13) is installed to burn and remove the tar. The stirrer is installed in the front end of blow-in pipe.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic view of the gravity-type separation apparatus. (Drawing includes non-English language text)    Gravity-type separation apparatus (10)    Cylindrical structure (11)    Cooling jacket (12)    Burner (13)    Collection tank (16)