A method of manufacturing an optical element (69, 149, 171, 203, 225) provided with mutually adjoining optical sub-elements (71, 155, 193, 219, 241) which are mutually arranged in a pattern such as, for example, a microlens array (69, 171, 203) with a two-dimensional orthogonal or hexagonal matrix of spherical lenses (71, 193, 219) or a faceted lens (149, 225) with a two-dimensional orthogonal matrix of facets (155, 241). According to the method, the optical element (69, 149, 171, 203, 225) is manufactured by means of a mould (7, 147) by a replication technique. The mould (7, 147) is manufactured from a ductile metal and is given a mould shape (83, 161) which corresponds to the pattern of sub-elements (71, 155, 193, 219, 241) by means of a die (65, 129) having a die surface (67, 131) which corresponds to the optical sub-element (71, 155, 193, 219, 241) and which is imprinted in the mould (7, 147) with a predetermined force in consecutive positions in accordance with the pattern. Preferably, the mould (7, 147) is provided with a surface smoothness desired for the optical element (69, 149, 171, 203, 225) before the mould shape (83, 161) is provided. The optical elements (69, 149, 171, 203, 225) manufactured by the method have a particularly high dimensional accuracy and a particularly large optically useful surface area. A device (1, 95) for implementing a method according to the invention comprises a workpiece holder (3) for fastening the mould (7, 147) to be manufactured, a tool holder (45, 91) for fastening the die (65, 129), and a positioning device (11). The tool holder (45, 91) comprises a straight guide (53) which is displaceable relative to the workpiece holder (3) by means of the positioning device (11), and a die holder (57, 93) which is guided with sliding possibility relative to the straight guide (53) and which bears on a stop (63) of the straight guide (53) under the influence of a predetermined elastic pretensioning force. A microlens array (171) manufactured by the method is used in a picture display device (169) which is provided with a liquid crystal display panel (181). Another microlens array (203) manufactured by the method is used in a solid state image sensor device (207) provided with a semiconductor body (209) with a charge coupled device (215, 217) and a pattern of image sensor elements (213). A faceted lens (225) manufactured by the method is used in a device (221) for manufacturing a front panel (223) for a colour picture tube.