A heat exchanger has a plurality of intermediate plates arranged one atop the other to form a stack having first and second ends. At least one first fluid channel through conducts a first fluid and at least one second fluid channel through conducts a second fluid. The intermediate plates are geometrically configured to define at least a portion of each of the first and second fluid channels. An end plate is arranged on one of the ends of the stack and a first inlet opening communicates with the first fluid channel for introducing the first fluid and a first outlet opening communicates with the first fluid channel for conducting the first fluid out of the heat exchanger. A second inlet opening communicates with the second fluid channel for introducing the second fluid and a second outlet opening communicates with the second fluid channel for conducting the second fluid away from the heat exchanger. The end plate has at least one expansion zone for reducing the stiffness thereof.