To provide a solution treatment method capable of treating a solution, in which a resin component is dissolved, for a short time, and an apparatus therefor.

The solution treatment apparatus is constituted so as to separate the solution, which is formed by dissolving the resin component in a solvent, into the gaseous solvent and the solid resin and equipped with an evaporation/separation tank (26) for storing a liquid heated to a temperature higher than the boiling point of the solution, a solution inflow port (27) for injecting the solution in the evaporation/separation tank and a gaseous solvent discharge port (31) for discharging the gaseous solvent formed in the evaporation/separation tank.