A high‐performance frequency‐swept capacitance bridge detector for ion cyclotron resonance (ICR) spectrometry has been constructed in our laboratory. Although the basic design of the system is similar to that of previously reported bridge circuits, careful design, layout, construction, and component selection have resulted in excellent frequency‐swept performance over a bandwidth of 15 kHz to 1 MHz. At a magnetic field strength of 1.0 T, this corresponds to a mass range of 15–1000 Daltons. Problems with base‐line drift and frequency‐dependent signal distortion common to many other designs have been significantly reduced. Circuit diagrams are included for all parts of the detector and frequency response curves have been included where appropriate. In addition, several simple circuit diagrams for support devices have also been included.