A diplex filter is formed by two impedance-transforming filters with separate transmission frequency ranges and with separate cut-off frequency ranges and a connection node at which two series elements of the two filters are connected. These two series elements are each fashioned as a parallel oscillating circuit, each parallel oscillating circuit exhibiting a predetermined reactance in a midband of the respective transmission frequency range and a parallel resonance in a midband of the respective cut-off frequency range. The diplex filter can be realized in a simple and cost-effective manner without ferrite-containing special components, for instance inductively coupled coils or tapped coils thereby allowing use thereof in a magnetic resonance tomograph, for example.