Solid-state sensor for measuring antimony in molten non-ferrous metals is developed employing Na-beta-Al2O3 + NaSbO3 composite solid electrolyte. The solid-state antimony sensor is schematically represented as M, Na-ref // Na-beta-Al2O3 + NaSbO3 // Sb-melt, M. The antimony sensor has been tested in Sn-Sb melt at 733 K, Zn-Sb melt at 793 K and Cu-Sb melt at 1423 and 1473 K. The measurements were conducted in dilute alloys containing less than 1 wt% Sb. The antimony content of the alloy samples was analysed by AAS. The measured e.m.f. of antimony sensor was found to be Nemstian with a slope of - RT/3F when plotted against in X(Sb).