To provide a plate type heat exchanger compact, excellent in heat transfer performance, high in withstand pressure and capable of using high pressure refrigerant.

In this plate type heat exchanger, a seal part 4 formed to lead inflow port and outflow port of heat exchange fluid into the inside and a heat transfer surface element 3 arranged to form a flow passage within the seal part 4 and formed into a projecting shape in a thickness direction of a plate 1 are provided, and a plurality of sheets of plates 1 are laminated to form the heat exchanger. The heat exchanger is provided with the seal part 4 having the heat transfer surface element 3 having an upper end part 6 having a flat projecting top part, a flat part 5 to be a bottom surface on an outer peripheral part of the flow passage, and a crest-shaped part 7 rising from the flat part 5 and having the top part formed into a plane shape.