We observe and study the reflection and interference in the two-layer thin film composed of a conductive
layer of ITO and dispersed particles of magnetic fluid (magnetite). In an electric field the equivalent
thickness of the membrane is increased by varying the thickness of the second layer. At a certain value of
the electric field the layer becomes unstable, its thickness varies periodically, autowave process leading to
the characteristic active centers (pacemakers), spiral waves (reverberators) was observed