A reactor structure has a heat transfer layer stacking construction with a stack of heat-conductive plate elements which, alternating in the stacking direction, bound one catalyst-filled reactor layer and one tempering layer respectively, adjacent plate elements being connected in a fluid-tight manner on at least two closed side areas. The plate elements on the closed side areas are bent in a U-shape and are arranged with U-side flanks which rest against one another in the stack such that the reactor layers have a larger height than the tempering layers. In addition or as an alternative, heat-conductive corrugated ribs are inserted at least in the reactor layers which are higher than the tempering layers.