A small-signal analysis is carried out for a geometry consisting of two parallel conducting planes, with a magnetized plasma resting on the one plane, and a vacuum gap between the plasma and the other. Each of the solutions found to fit the boundary conditions consists of a superposition of two ‘transverse’ wave-functions with one and the same longitudinal propagation constant. Numerical solution of the dispersion relations yields the following. (i) A set of slow waves, in good agreement with the well-known quasi-static approximation. (ii) Fast waves, which approximate TM waves (Hz ≐ 0) propagating only at relatively high frequencies. (iii) Fast waves propagating in the same frequency range as the TM waves, but with negligible longitudinal electric field component Ez, thus resembling TE waves. (iv) A set of waves with a dispersion which resembles that obtained from coupling between fast forward and slow backward modes of propagation. (v) A single wave, not obtainable from the slow-wave approximation which resembles the helicon wave of the one-dimensional case, with the frequency approaching the cyclotron frequency at small wavelengths, provided the magnetic field is relatively strong (ωc < ωp), the spacing between the conducting planes not too narrow and the fill-factor not too small. For relatively weak magnetic fields (ωc < ωp), this wave appears as a surface wave with frequency approaching the lower hybrid frequency at small wavelengths.