Novel sol–gel glass thin films containing 12-molybdophosphoric acid were achieved on the surface of a glassy carbon electrode by the sol–gel technique. The electrochemical behavior of the modified electrode was studied in detail. The new chemically modified electrode was shown to exhibit a high electrocatalytic response for the reduction of iodate. Iodate in table salt was determined amperometrically in pH 2.6 acidic aqueous solution at the modified electrode with satisfactory results. The method had a linear range from 5×10 −6 to 6×10 −3 M and a detection limit of 1×10 −6 M (signal-to-noise ratio 3).