A baking plate, for a baking plate device of a baking oven for producing crispy-brittle wafers baked from a baking mass in a baking process under overpressure, - wherein the baking plate comprises a plate-shaped base body following a main extension plane, - wherein the base body has an external baking surface forming a side/a part of the surface of an overpressure baking mould during the baking process, - wherein the base body has a back surface on the outer side opposite the baking surface, via which an input of energy is supplied to heat the baking plate during the baking process, - wherein a tensioning groove with a first groove flank, a second groove flank and a groove base is recessed in the back surface of the base body, - wherein a tensioning bar is provided, which is inserted into the tensioning groove and thus between the groove flanks (9, 10), - wherein the tensioning bar has a first tensioning surface, a second tensioning surface and a base surface, - wherein multiple first tensioning means and multiple second tensioning means are provided, which can be brought into a tensioned position and which are formed in particular as tensioning screws, characterized - in that the tensioning means (16, 17), in their tensioned position, engage on the tensioning bar and, starting from the tensioning bar, project on both sides through the groove flanks (9, 10) into the base body and also engage there, - and in that the tensioning means (16, 17), in their tensioned position, pull the groove flanks (9, 10) inwards towards or against the tensioning bar, thereby convexly bending the baking surface of the base body and holding the baking plate in a pretensioned position. - wherein the baking plate comprises a plate-shaped base body following a main extension plane, - wherein the base body has an external baking surface forming a side/a part of the surface of an overpressure baking mould during the baking process, - wherein the base body has a back surface on the outer side opposite the baking surface, via which an input of energy is supplied to heat the baking plate during the baking process, - wherein a tensioning groove with a first groove flank, a second groove flank and a groove base is recessed in the back surface of the base body, - wherein a tensioning bar is provided, which is inserted into the tensioning groove and thus between the groove flanks (9, 10), - wherein the tensioning bar has a first tensioning surface, a second tensioning surface and a base surface, - wherein multiple first tensioning means and multiple second tensioning means are provided, which can be brought into a tensioned position and which are formed in particular as tensioning screws, characterized - in that the tensioning means (16, 17), in their tensioned position, engage on the tensioning bar and, starting from the tensioning bar, project on both sides through the groove flanks (9, 10) into the base body and also engage there, - and in that the tensioning means (16, 17), in their tensioned position, pull the groove flanks (9, 10) inwards towards or against the tensioning bar, thereby convexly bending the baking surface of the base body and holding the baking plate in a pretensioned position.