To provide a utilization system of plant-based biomass in which plant-based biomass can be pluralistically utilized.

The utilization system of plant-based biomass includes: an extraction means 1 to extract essential oil, a fragrant material, a pigment, or oil and fat by microwave heating using methanol as a solvent from plant-based biomass, which is reduced to splinters and raw, dried, or obtained after oil expression; a separation means 2 to separate the plant-based biomass after extraction from the solvent; a methanol recovery means 3 to distill the separated solvent; a gasification means 4 to decompose the separated plant-based biomass by a catalyst and achieve gasification; and a methanol synthesis means 5 to synthesize methanol from hydrogen and carbon monoxide obtained from the gasification. While reusing the methanol recovered by the methanol recovery means in the extraction means of essential oil, a shortage of methanol is covered by the synthesized methanol.