The invention relates to a nozzle head, an apparatus and method for subjecting a surface of a substrate to successive surface reactions of at least a first precursor (A) and a second precursor (B). The nozzle head having an output face comprises at least one precursor nozzle for supplying precursor (A, B) to the surface of the substrate and at least one discharge channel for discharging precursor (A, B) from the surface of the substrate. The output face comprises in the following order: a discharge channel, at least one at least one precursor nozzle arranged to supply the first precursor (A) and the second precursor (B) and a discharge channel.
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