This paper investigates winding losses in an induction coil and radiated emissions of electrodeless lamps. As the operating frequency of electrodeless lamps is high, the AC resistance of an induction coil increases by the influence of skin effect and proximity effect. In order to calculate the magnetic field at the coil for the calculation of AC resistance, we replace the winding turns of the coil with the parallel of separated circular coils in the analysis. Therefore, the AC resistance of solid and litz wires in an induction coil is easily derived in this paper. This paper also investigates radiated emissions of electrodeless lamps. From the analysis and the experiment, it is clarified that the radiated emissions at discharging is higher than that before discharging because the harmonic-components of the current of the induction coil at discharging are larger than that before discharging.