A spin head includes a rotatable plate, first chucking pins and second chucking pins for supporting a edge portion of a substrate loaded on the plate, and a driving unit for selectively driving the first and second chucking pins. The driving unit includes a first magnet connected to the first chucking pin and disposed at a first height, a second magnet connected to the second chucking pin and disposed at a second height, and a driving magnet for driving the first and second magnets. The driving magnet is elevated by means of an elevating member to selectively apply a magnetic force to the first or second magnet and moves in the radius outside direction of the first or second chucking pin due to a magnetic force.