Abstract: The device includes a housing, a means for heating the housing, and a means for supporting, in the housing, at least one group composed of plates of malleable material under pressure at the temperature established in the housing. Moreover, the group includes generally flat molds and each mold includes at least one non malleable pitted surface under pressure at said temperature. The molds are inserted between the plates. Means are envisaged to apply a roughly uniform pressure, oriented perpendicularly to the surface of the plates to the entire group. This pressure is suitable for causing the production of convex surfaces of microlenses on the sides of the plates, which are opposite said pitted surfaces of the molds.