A deposition apparatus comprises a chamber, a deposition material supplier positioned in the chamber and configured to contain and supply a deposition material, a substrate holder disposed in the chamber and configured to hold a substrate such that a major surface of the substrate faces the deposition material supplier; and a mask retainer disposed in the chamber and configured to retain a mask disposed over the major surface of the substrate. The mask retainer comprises a base, and a plurality of magnets coupled to the base, at least one of the plurality of magnets being movable with respect to the base, the plurality of magnets being configured to apply magnetic force to the mask such that the mask is fixed to the substrate without substantial movement of the mask with respect to the substrate during deposition of the deposition material.