A device for heating thermoplastic preforms for use in blow moulding or thermoforming, with at least one base body (1.0, 2.0), on the surface of which at least one first layer (1.1, 2.1) is formed, which has a plurality of electrical heating resistors in the form of conductor loops arranged geometrically in a planar manner, wherein the at least one base body (1.0, 2.0) is formed from a ceramic material and electrically conductive connections are achieved by means of vias in the material, and the at least one base body (1.0, 2.0) further comprises a number of contact elements corresponding to the number of electrical heating resistors, via which the heating resistors can be connected independently of one another to a controllable current source (1.2, 2.2), wherein a plurality of heating resistors can each be controlled individually and the electrical heating resistors are formed from a doped ceramic or polymer material or with an electrically conductive metal or oxide layer and are applied to an electrically insulating carrier layer which is electrically insulated on a side facing the at least one base body (1.0, 2.0) and the electrical heating resistors have a thickness in the range 1 μlm to 100 μm and a width in the range 0.001 mm to 5 mm, wherein the electrical heating resistors are configured such that a defined temperature profile with locally differentiated temperature distribution can be generated by controlling the electrical current applied to the contact elements or the electrical voltage applied to the contact elements, which temperature profile can be transmitted to the preform body via an outer contact layer (1.3, 2.3) formed on the first layer (1.1, 2.1), the device being configured such that the outer contact layer (1.3, 2.3) corresponds to at least one section of the surface of the preform body, characterized in that at least one base body (1.0, 2.0) is formed from a plurality of individual modules which can be connected to one another, and at least one heating resistor is present on each of the individual modules, so that, depending on the type, size, shape and number of the individual modules, an adapted base body can be provided for the manufacture of a specific product. with at least one base body (1.0, 2.0), on the surface of which at least one first layer (1.1, 2.1) is formed, which has a plurality of electrical heating resistors in the form of conductor loops arranged geometrically in a planar manner, wherein the at least one base body (1.0, 2.0) is formed from a ceramic material and electrically conductive connections are achieved by means of vias in the material, and the at least one base body (1.0, 2.0) further comprises a number of contact elements corresponding to the number of electrical heating resistors, via which the heating resistors can be connected independently of one another to a controllable current source (1.2, 2.2), wherein a plurality of heating resistors can each be controlled individually and the electrical heating resistors are formed from a doped ceramic or polymer material or with an electrically conductive metal or oxide layer and are applied to an electrically insulating carrier layer which is electrically insulated on a side facing the at least one base body (1.0, 2.0) and the electrical heating resistors have a thickness in the range 1 μlm to 100 μm and a width in the range 0.001 mm to 5 mm, wherein the electrical heating resistors are configured such that a defined temperature profile with locally differentiated temperature distribution can be generated by controlling the electrical current applied to the contact elements or the electrical voltage applied to the contact elements, which temperature profile can be transmitted to the preform body via an outer contact layer (1.3, 2.3) formed on the first layer (1.1, 2.1), the device being configured such that the outer contact layer (1.3, 2.3) corresponds to at least one section of the surface of the preform body, characterized in that at least one base body (1.0, 2.0) is formed from a plurality of individual modules which can be connected to one another, and at least one heating resistor is present on each of the individual modules, so that, depending on the type, size, shape and number of the individual modules, an adapted base body can be provided for the manufacture of a specific product.