A hydrogen ion-selective electrode was prepared using 5,11,17,23-tetra-tert-butyl-25,26,27,28-tetracyanometoxycalix[4]arene and the possibility of its use as a perchlorate ion-selective electrode was investigated using its characteristic of becoming perchlorate sensitive in acidic regions. The electrode of the optimum characteristic had a composition of 1% ionophore, 66% o-NPOE, and 33% PVC. This electrode exhibited a linear response over the range 1.0 x 10(-1)-1.0 x 10(-5) M of perchlorate with a slope of 48.7 +/- 0.5 mV per p[ClO(4)]. The effects of the pH and the membrane composition were also investigated. The lifetime of the electrode was at least 4 months and its response time was 10(-15) s. The selectivity coefficients of some anions were calculated by the matched potential method.