A transformerless inverter for feeding electrical energy from a direct current source into an alternating current grid, with an inverter bridge and with a DC/DC converter connected upstream of the inverter bridge, the DC/DC converter converting a DC input voltage applied between two input lines (6 and 7) of the inverter into a DC link voltage applied between two input lines (8 and 9) of the inverter bridge, the inverter bridge converting the DC link voltage applied at its input lines (8 and 9) into an AC output voltage, characterized - in that the DC/DC converter comprises two resonant circuits (12', 12") each comprising a resonant inductance and a resonant capacitance, - wherein the resonant inductance and the resonant capacitance are connected in series between an input and an output of the respective resonant circuit (12', 12"), - wherein the input of the respective resonant circuit (12', 12") in each case is electrically conductively connectable via at least two clocked switches (S1 and S2) to one of the two input lines (6 and 7) of the inverter on the one hand and to an intermediate potential line carrying an intermediate potential in between on the other hand, and - wherein the output of the respective resonant circuit (12', 12") is alternately connectable to the two input lines (8 and 9) of the inverter bridge in an electrically conductive manner, and - in that the DC/DC converter comprises at least one alternating current return path which is electrically conductively connected or connectable on the input side to the input lines (6 and 7) of the inverter or the intermediate potential lines and on the output side to the input lines (8 and 9) of the inverter bridge, - wherein the input lines (6 and 7) of the inverter and the input lines (8 and 9) of the inverter bridge are galvanically separated from each other in a capacitive manner. - in that the DC/DC converter comprises two resonant circuits (12', 12") each comprising a resonant inductance and a resonant capacitance, - wherein the resonant inductance and the resonant capacitance are connected in series between an input and an output of the respective resonant circuit (12', 12"), - wherein the input of the respective resonant circuit (12', 12") in each case is electrically conductively connectable via at least two clocked switches (S1 and S2) to one of the two input lines (6 and 7) of the inverter on the one hand and to an intermediate potential line carrying an intermediate potential in between on the other hand, and - wherein the output of the respective resonant circuit (12', 12") is alternately connectable to the two input lines (8 and 9) of the inverter bridge in an electrically conductive manner, and - wherein the resonant inductance and the resonant capacitance are connected in series between an input and an output of the respective resonant circuit (12', 12"), - wherein the input of the respective resonant circuit (12', 12") in each case is electrically conductively connectable via at least two clocked switches (S1 and S2) to one of the two input lines (6 and 7) of the inverter on the one hand and to an intermediate potential line carrying an intermediate potential in between on the other hand, and - wherein the output of the respective resonant circuit (12', 12") is alternately connectable to the two input lines (8 and 9) of the inverter bridge in an electrically conductive manner, and - in that the DC/DC converter comprises at least one alternating current return path which is electrically conductively connected or connectable on the input side to the input lines (6 and 7) of the inverter or the intermediate potential lines and on the output side to the input lines (8 and 9) of the inverter bridge, - wherein the input lines (6 and 7) of the inverter and the input lines (8 and 9) of the inverter bridge are galvanically separated from each other in a capacitive manner. - wherein the input lines (6 and 7) of the inverter and the input lines (8 and 9) of the inverter bridge are galvanically separated from each other in a capacitive manner.