The invention relates to a heat exchanger for an electronics cabinet with a folded surface profile in which, alternatingly on both faces every other fold is closed off gastight or dustproof by a cross cover. With such an air/air heat exchanger the waste heat from the interior of an electronics cabinet can be dissipated to the outside when the electronics cabinet is closed dusttight. To facilitate production of the folded surface profile, the cross covers are integrally formed onto the folds. Such a folded surface profile, in which the folds and the cross covers form one integral component, is preferably produced as a deepdrawn part, so it is possible to make the component from plastic. In another embodiment, the folded surface profile can be a plastic injection molding.