The plate heat exchanger is fixed by numbers of thin and corrugated heat plates, hanged between the carrying baron the above and the guide bar on the below. These heat plates provide flow channels for two kinds of fluid, and the chevrons on the heat plates make the turbulent flow and play a role to support the plate against the pressure difference between the two fluids. The plate pack is to be placed between the fixed cover and the movable cover,and fixed with tie bolts. Gasket is attached to the heat plate which forms flow channel and acts seal up the fluid not to leak to the outside. The number of the heat plate is determined according to the amount of fluid, physical properties of fluid, the pressure drop and thermal condition. The covers prevent the plates bended from the difference ofpressure. In the assembly of plate, the surface with gasket is directed to the fixed cover and each plate is hanged in opposite direction alternately. And two fluids cannot be mixed and separated by a thin plate. One fluid always flows in "A" channel and the other fluid always flow in "B" channel.