Calix[4]arenesulfonic acid complexation with perchloric acid is studied. The stoichiometric composition of the complex is shown to be calix[4]arene/HClO4 = 1/1. The complex is most stable against humidity changes as far as its proton-conducting properties are concerned. Its specific proton conductivity varies from 3 × 10–3 to 5 × 10–2 S/cm; the conductivity activation energy is 0.16 ± 0.04 eV. The studying of the effect of HClO4 amount on the samples’ physico-chemical properties at low humidity showed the proton transfer in the material to be determined by the crystallites’ bulk, rather than surface, characteristics.