A new low‐frequency cutoff for them=−1 fast wave in a cold cylindrical plasma in the ion‐cyclotron frequency range is reported for the completely‐filled plasma waveguide. The presence of a vacuum gap between the plasma and the conducting wall enables the wave to propagate to arbitrarily small frequencies. For &ohgr;∼&ohgr;ci, this mode is a surface wave and undergoes a resonance at the ion‐cyclotron frequency.