Apparatus suitable for extracting and removing rare earth metal ions from a plating solution containing rare earth metal ions as impurities, using an extracting solution of an extractant in a water-insoluble organic solvent having a lower specific gravity than water, said apparatus comprising an extraction tank, a plating solution feed line fitted at a distal end with an atomizing nozzle to atomize the plating solution, and positioned in an upper zone of the extraction tank, an extracting solution feed line fitted at a distal end with an atomizing nozzle to atomize the extracting solution, and positioned in a lower zone of the extraction tank, an outlet from the extraction tank for discharging plating solution from which rare earth metal ions have been extracted, another outlet from the extraction tank for discharging extracting solution having extracted rare earth metal ions therein, whereby in use the extracting solution is atomized from the nozzle at the distal end of the extracting solution feed line into the tank lower zone so as to flow upward, and the plating solution is atomized from the nozzle at the distal end of the plating solution feed line into the tank upper zone so as to flow downward, to bring the plating solution into contact with the extracting solution; an outlet partition defining a channel leading to the plating solution outlet from the lower zone, and separating the plating solution outlet from the upper zone, characterized in that said apparatus further comprises: a partition disposed in the extraction tank to divide it into an extraction compartment having said atomizing nozzles and a stationary compartment, a lower passage at a lower portion of the partition for communication of the plating solution between said compartments (8,9), and an upper passage at an upper portion of the partition for communication of the extracting solution between said compartments (8,9). an extraction tank, a plating solution feed line fitted at a distal end with an atomizing nozzle to atomize the plating solution, and positioned in an upper zone of the extraction tank, an extracting solution feed line fitted at a distal end with an atomizing nozzle to atomize the extracting solution, and positioned in a lower zone of the extraction tank, an outlet from the extraction tank for discharging plating solution from which rare earth metal ions have been extracted, another outlet from the extraction tank for discharging extracting solution having extracted rare earth metal ions therein, whereby in use the extracting solution is atomized from the nozzle at the distal end of the extracting solution feed line into the tank lower zone so as to flow upward, and the plating solution is atomized from the nozzle at the distal end of the plating solution feed line into the tank upper zone so as to flow downward, to bring the plating solution into contact with the extracting solution; an outlet partition defining a channel leading to the plating solution outlet from the lower zone, and separating the plating solution outlet from the upper zone, a partition disposed in the extraction tank to divide it into an extraction compartment having said atomizing nozzles and a stationary compartment, a lower passage at a lower portion of the partition for communication of the plating solution between said compartments (8,9), and an upper passage at an upper portion of the partition for communication of the extracting solution between said compartments (8,9).