A method of providing a patterned relief of cured photoresist on a flat substrate surface, the substrate surface being provided with a layer of a UV-light curable liquid photoresist, after which the photoresist is brought into contact with a UV light-transparent mould having a relief which is complementary to the patterned relief to be provided and which is subsequently cured by exposure to a UV light source, thereby forming the patterned relief, after which the mould of the cured relief is removed, characterized in that a hollow circular-cylindrical mould which rotates about its cylinder axis is used as the mould, the outside of the cylinder surface being provided with the relief and the cylinder axis extending parallel to the substrate surface, the interior of the mould being provided with an elliptic mirror having a first and a second focal line, said focal lines extending parallel to the substrate surface and the first focal line coincided with the longitudinal axis of the UV light source, and the second focal line coinciding with a tangent of the mould to the substrate surface, so that the photoresist is cured at the location of the second focal line, thereby forming a part of the patterned relief, while the substrate surface is kept in non-slip contact with the rotating mould.