The invention relates to a heating device having a heating arrangement in a housing through which a fluid medium can flow in a longitudinal direction, wherein the at least one heating arrangement comprises at least two grid elements as heat exchanger plates with openings through which the medium flows, the grid planes of which are embodied for the exchange of heat energy between the plate and the fluid medium, at least one heating element, in particular a PTC element, arranged between the grid elements, wherein the at least one heating arrangement is arranged in the housing in such a way that the grid planes of the grid elements are arranged substantially perpendicularly to the longitudinal direction, so that the flow of medium is oriented substantially perpendicularly to the grid planes, wherein the grid elements and the at least one heating element are arranged braced relative to one another by means of at least one tensioning element so that they touch, and wherein the grid elements each have at least one contact region and are arranged in such a way that they absorb the heat energy from the at least one heating element substantially via the contact region.The heating device can be manufactured in simplified production and at low costs, environmental aspects also being taken into account during operation of the heating device.