Abstract: Manufacturing a plate heat exchanger calls for punching plates, each of which having at least one projection in the form of a hollow truncated cone, cleaning surfaces of the plates, composing a plate assembly by mounting the projection of one plate into opening of an adjacent plate. A predetermined gap between adjacent surfaces of the plates is maintained, a channel for passing a heat carrier is formed. A soldering paste solution based on copper hydrocarbonate and nickel salts is prepared, into which the plate assembly is immersed, the applied solution is dried. The plate assembly is placed into a high-temperature through-type conveyor furnace with a protective medium containing free hydrogen. Two temperature zones are provided along the way of movement of the plate assembly. The plate assembly is annealed in the first temperature zone and then soldered and covered with the copper-based alloy in the second temperature zone.