NOVELTY - Biomass is pre-hydrolysis-processed on pressurization/heating conditions and aqueous suspension of biomass is supplied more continuously through the supply port of a continuous hydrolysis apparatus. While discharging pre-hydrolysis-processing suspension more continuously through discharge port of a hydrolysis apparatus, pre-hydrolysis-processing liquid is separated from pre-hydrolysis-processing suspension. A vapor phase containing furfural is separated from liquid phase by sending and carrying out flash distillation in concentration-separation apparatus.    USE - Continuous production of furfural used as intermediate for preparing pharmaceuticals and plastic raw material.    ADVANTAGE - The method efficiently and economically provides furfural.    DETAILED DESCRIPTION - Biomass is pre-hydrolysis-processed on pressurization/heating conditions and aqueous suspension of biomass is supplied more continuously through the supply port of a continuous hydrolysis apparatus, and moving the inside of an apparatus. While discharging pre-hydrolysis-processing suspension more continuously through the discharge port of a hydrolysis apparatus, the pre-hydrolysis-processing liquid is separated from pre-hydrolysis-processing suspension in an apparatus from the intermediate extraction opening provided with the solid-liquid-separation apparatus in the intermediate position of the supply port of a hydrolysis apparatus, and discharge port continuously in the state which maintained the temperature and pressure of the pre-hydrolysis processing. A vapor phase containing furfural is separated from liquid phase by sending and carrying out flash distillation in concentration-separation apparatus. The separated vapor phase is condensed and furfural containing aqueous solution is obtained.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic structure of apparatus for continuous production of furfural. (Drawing includes non-English language text)    Aqueous suspension material supply line (1)    Pre-hydrolysis-processing suspension-collecting line (2)    Pre-hydrolysis-processing liquid transfer line (3)    Furfural aqueous solution collecting line (4)    Aqueous solution collecting line (5)