From an electrical point of view a planar lipid bilayer can be considered as a non-perfect capacitor; it can be presented as an ideal capacitor in parallel with resistor. In this study the whole measuring system including planar lipid bilayer was modeled by an equivalent electric circuit in Spiceopus software. Such a model gives additional information of experimentally obtained results. In this way we analyze measurements of transmembrane voltage that appears on planar lipid bilayer as consequence of linear rising current. Small voltage drops were obtained before the planar lipid bilayer breakdown. The model showed that effective current on planar lipid bilayer is actually much smaller than the current applied with current generator and should be used in calculations of a conductance related to voltage drops.