An apparatus is described for depositing a film on a substrate from a plasma. The apparatus comprises an enclosure, a plurality of plasma generator elements disposed within the enclosure, and means, also within the enclosure, for supporting the substrate, Each plasma generator element comprises a microwave antenna having an end from which microwaves are emitted, a magnet disposed in the region of the antenna end and defining therewith an electron cyclotron resonance region in which a plasma can be generated, and a gas entry element having an outlet for a film precursor gas or a plasma gas. The outlet is arranged to direct gas towards a film deposition area situated beyond the magnet, as considered from the microwave antenna, the outlet being located above the ends of the magnets nearest the film deposition area, and thus being located in, or above, the hot electron confinement envelope.