To provide a method for recovering a high-purity alkali metal hydroxide aqueous solution of aromatic dihydroxy compound by inexpensively treating a waste aromatic polycarbonate resin (e.g., an unneeded aromatic polycarbonate resin product such as information medium material such as CD, and automotive head lamp lens and sheet) in large quantities.

In the method for recovering a purified alkali metal hydroxide aqueous solution of aromatic dihydroxy compound by depolymerizing a waste aromatic polycarbonate resin, an unpurified alkali metal hydroxide aqueous solution of aromatic dihydroxy compound after the depolymerizing reaction is washed with an organic solvent obtained by condensing the vapor evaporated from a reaction tank by use of a process having the reaction tank for reacting the waste aromatic polycarbonate resin dissolved to the organic solvent with an alkali metal hydroxide aqueous solution, a condensing device for condensing the organic solvent vapor evaporated from the reaction tank, and a storage tank for receiving the condensed organic solvent.

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