A planar luminous element with the following features: A layer assembly with a first electrode layer, a second electrode layer and at least one light-emitting layer interposed between said layers, wherein a plurality of contact regions for contacting the first electrode layer and at least one contact region for contacting the second electrode layer are provided, wherein at least one contact region (12, 13) of the contact regions (12, 13) provided for contacting has a trimmable resistance element (12a, 13a; 21a, 22a) or wherein a trimmable resistance element is connected between a contact region provided for contacting the first electrode layer and a contact region provided for contacting the second electrode layers, wherein the resistance value of the trimmable resistance element (12a, 13a; 21a, 22a; 40) can be set to a modified resistance value, characterized in that the layer assembly is connected with a base element, in particular with a circuit board, and the base element has intermediate contact regions (26, 27) on one of the first main surface facing the layer assembly, which are connected with the contact regions (12, 13) of the layer assembly, and external contacts (21, 22) on a second main surface, which are electrically connected to the associated intermediate contact regions (26, 27) on the first main surface of the base element, wherein the trimmable resistance element (21a, 22a) is connected in series between the intermediate contact regions (26, 27) on the first main surface of the base element, which is electrically connected with the at least one contact region (12, 13) of the layer assembly provided for contacting, and the assigned external contact (21, 22) wherein the trimmable resistance element has a trimmable thick layer resistance structure, a trimmable thin layer resistance structure, a trimmable SMD resistance element or a trimmable integrated resistance structure or wherein the trimmable resistance element has an adjustable potentiometer or a programmable electronic load circuit. A layer assembly with a first electrode layer, a second electrode layer and at least one light-emitting layer interposed between said layers, wherein a plurality of contact regions for contacting the first electrode layer and at least one contact region for contacting the second electrode layer are provided, wherein at least one contact region (12, 13) of the contact regions (12, 13) provided for contacting has a trimmable resistance element (12a, 13a; 21a, 22a) or wherein a trimmable resistance element is connected between a contact region provided for contacting the first electrode layer and a contact region provided for contacting the second electrode layers, wherein the resistance value of the trimmable resistance element (12a, 13a; 21a, 22a; 40) can be set to a modified resistance value, characterized in that the layer assembly is connected with a base element, in particular with a circuit board, and the base element has intermediate contact regions (26, 27) on one of the first main surface facing the layer assembly, which are connected with the contact regions (12, 13) of the layer assembly, and external contacts (21, 22) on a second main surface, which are electrically connected to the associated intermediate contact regions (26, 27) on the first main surface of the base element, wherein the trimmable resistance element (21a, 22a) is connected in series between the intermediate contact regions (26, 27) on the first main surface of the base element, which is electrically connected with the at least one contact region (12, 13) of the layer assembly provided for contacting, and the assigned external contact (21, 22) wherein the trimmable resistance element has a trimmable thick layer resistance structure, a trimmable thin layer resistance structure, a trimmable SMD resistance element or a trimmable integrated resistance structure or wherein the trimmable resistance element has an adjustable potentiometer or a programmable electronic load circuit.