When the pulp flows to the tank in the magnetic separator, the mineral granules spreads under the impact of the water flow from the show pipe. As a result of the magnetic force, the magnetic minerals concentrate as a lump or a chain. This lump or chain is then absorbed on the cylinder owing to the magnetic force. When the magnetic lump or chain rotates with the cylinder, gangues and other non-magnetic minerals falls off from the lump or chain and are then discharged with the pulp. The lump or chain left at the wall of the cylinder is ore concentrate. It is then discharged off from the magnetic separator with water.