To provide an apparatus for converting plant resources by phase separation to efficiently produce lignin derivatives and hydrolyzed glucides.

The conversion apparatus is one comprising a raw material pretreatment section 2, a concentrated acid treatment section 3, and a recovery section 4, wherein the raw material pretreatment section 2 comprises a raw material agitation and drying kettle 10 provided with a feed port for a phenol and a solvent and defatting the raw material to form a defatted raw material in the form of a phenol-sorbed wood fluor 16, the concentrated acid treatment section 3 is provided with an agitation tank 20 for mixing the phenol-sorbed wood flour 16 with a concentrated acid, a vibration reactor 22 connected to the agitation tank 20, and a separator/extractor 25 that performs the liquid-liquid separation between the formed lignin layer and the formed concentrated acid layer by the reaction between the phenol-sorbed wood fluor 16 and the concentrated acid and recovers the concentrated acid layer from the separator/extractor 25, and the recovery part 4 comprises a crystallizer or mixer 30 and recovers lignophenol from the lignin layer.