The invention relates to a bidirectional DC-DC converter for high voltages which is as simple and low-loss as possible. The bidirectional DC-DC converter (1) comprises an input stage (2) for converting a DC input voltage into a first AC voltage, a transformer (3) for transforming the first AC voltage into a second AC voltage, and an output stage (4) for converting the second AC voltage into a DC output voltage, wherein at least one of the input stages (2) and/or output stages (4) comprises a branch of a multi-level converter (5) comprising a first number of active first semiconductor switches (61) for supplying the first and/or second AC voltage(s).