In this paper, a fully soft switched two-level DC-DC Boost converter is proposed. The converter is used only one auxiliary cell to create the soft switching conditions for all semiconductor devices. The auxiliary cell contains one auxiliary switch, one resonant capacitor, one resonant inductor and one auxiliary diode. The auxiliary switch creates the soft switching conditions by control of resonant elements. Besides, the auxiliary cell is not located in the main power path and cannot decrease the converter efficiency. It has simple operation modes. Besides, the proposed soft-switched converter is highly efficient while the control circuit is simple and remains PWM. Furthermore, the use of two-level structure in the proposed topology creates a converter with high gain.Based on the mentioned advantages, the proposed converter is a suitable candidate to use in electric vehicles.The theoretical waveforms, operation modes and simulation results are considered to show the good characteristics of the proposed converter.