A preparative purification apparatus capable of adjusting a mixing ratio of a mobile phase and an elution solvent contained in a solution to be collected. A liquid feeding unit which feeds an elution solvent to an inlet of a trap column; a flow path switching unit which selectively connects an outlet of the trap column to one of a waste liquid flow path or a recovery flow path; a liquid feed amount measurement unit; and a flow path control unit which performs a control such that the flow path switching unit is connected to the recovery flow path when the amount of the elution solvent fed to the trap column reaches a predetermined initial waste liquid amount, and thereafter, the flow path switching unit is connected to the waste liquid flow path at a timing of reaching a predetermined solution recovery amount.