Disclosed is a heating plate for a flow heater having a substrate made of metal, a heating resistor arranged on one side of the substrate and fins arranged on an opposite side of the substrate. The fins are brazed to the substrate, made of corrugated sheet metal and provided with a series of cuts across ridges of the corrugated sheet metal. According to this disclosure, the ridges are compressed such that opposing surfaces on the inside of the ridges contact each other.