- Contacts metal/porous silicon and p/n device structures on porous silicon were studied by scanning electron microscopy in the electron‐beam‐induced current mode. It is shown that the drift processes are dominant in operation of porous silicon‐based devices. We present the theoretical analysis of electron‐beam‐induced current measurements and estimate such important parameters of device structures as: the width of the space‐charge region (several microns), charge state density in the space‐charge region (1014–1015 cm− 3), and electron drift length (up to 10− 3 cm). The spatial distribution of the electric field in space‐charge region was derived. The possibility of studying the influence of porous silicon/crystalline silicon interfaces on operation of porous silicon‐based devices has been illustrated.