The band‐bending potential profileV(x) in the space‐charge region of an amorphous semiconductor moves regidly in thexdirection, with increased bias, irrespective of the form of the density of localized statesN(E). A recent paper by Singh and Cohen [J. Appl. Phys. 51, 413 (1980)] which suggest this is not true is incorrect in this point. This property leads to simplified schemes for the analysis ofC‐Vmeasurements and field‐effect conductance measurements.