Apparatus for atomic layer deposition on a surface of a substrate includes a precursor injector head. The precursor injector head includes a precursor supply and a deposition space that in use is bounded by the precursor injector head and the substrate surface. The precursor injector head is arranged for injecting a precursor gas from the precursor supply into the deposition space for contacting the substrate surface. The apparatus is arranged for relative motion between the deposition space and the substrate in a plane of the substrate surface. The apparatus is provided with a confining structure arranged for confining the injected precursor gas to the deposition space adjacent to the substrate surface.