Abstract: The present invention concerns a plate heat exchanger for at least two heat exchanging fluids. The heat exchanger is permanently joined and includes at least one core of plates with corrugated heat exchanging plates (1-4) creating plate interspaces between one another, at least two end plates (5) as well as inlet devices (6) and outlet devices (6) for the heat exchanging fluids. At least one of the end plates (5) is equipped with at least one port hole communicating with an inlet channel or an outlet channel. At least one of the mentioned inlet devices (6) and outlet devices (6) has both a connection part (7) equipped with a channel and a transition part (8) with an envelope surface and equipped with a channel.