In experiment, Maxwell's displacement current flew through the structure containing a metal electrode, an air-gap insulating layer and a Langmuir monolayer situated on the water surface. This contactless arrangement provided a direct insight in the orientational motion of the monolayer constituting molecules. The effect of the surface pressure upon the molecular conformation was monitored by evaluating the vertical component of the dipole moment. The results were compared to and justified by the molecular dynamics calculation. These measurements and simulations were applied to a modified poly(3-alkyl-thiophene) having the polar metoxy chain ends.