If a circular coil excited with AC is facing to an infinite plane conductor, an electromagnetic force is produced by eddy currents induced in the conductor. This force varies characteristically with the amplitude and frequency of the current in the coil, with the quality and thickness of the conductor and with the distance between the coil and the conductor. So we make a precise analysis of these various characteristics by using Maxwell's equations. Furthermore, we make an experiment and obtain a very good agreement between the theoretical and the measured values of the force.