The invention relates to a heat exchanger to be used in particular in a waste incineration plant, wherein flue gasses are conducted along pipes through which steam is passed for the production of heated steam. The heat exchanger is comprised of shield pipes (8) and superheater pipes (15) provided immediately behind these. These shield pipes are embodied with a diameter different to that of the pipes which, viewed in the direction of slow, lie behind these. In some cases it is preferred to choose a larger diameter in order to create a lee for the pipes lying behind. In other cases on the other hand, a smaller diameter is possibly more effective because this may reduce the influence of the Von Karman vortices.