The dynamic behaviour of the measured signal of a power compensated DSC is studied in terms of linear response taking into account the measuring system, the sample, the reference, the control circuits, the heat transport coefficients and the heat losses. As a result it is shown that the apparatus (or Green’s) function of the DSC (including sample and heat transfer) is different from that necessary to desmear the sample heat flow. The quality of the extracted Green’s function is discussed for different measuring conditions.