Key words Stationary afterglow plasma, microwave diagnostics of plasma, electron heating with microwaves, dissociative recombination, electron temperature dependence of recombination, molecular neon ions. PACS 34. 80, 52.20, 52.70 Three dual mode microwave apparatus (one using S-band and two using X-band) have been developed to determine ambipolar diffusion and electron-ion recombination rates under conditions such that Tgas = 300K and Te is varied from 300 K to 6300 K, in the afterglow period of the dc glow discharge. The T M010 cylindrical cavity (in S-band) and T M011 open cylindrical cavity (X-band) are used to determine the electron density during the afterglow period and a non-resonant waveguide mode is used to apply a constant microwave heating field to the electrons. To test the properties of the apparatus the neon afterglow plasma has been investigated. At Te = 300 K a value of α(Ne (X-band) obeyed over the range 300 ≤ Te ≤ 6300K are in good agreement with some other previous measurements. The simplicity of the X-band microwave apparatus also allows the measurements of the gas temperature dependency and the study of electron attachment and may be used simultaneously with optical or mass spectrometry investigations.