The technology of fabrication of anion-selective light-addressable potentiometric sensors (LAPS) by using a solid-state microelectronic device integrated with an ion-recognition membrane has been elaborated. The nitrate sensor with ion-exchange membrane exhibits a linear response interval of 3 × 10^-5 to 1 × 10^-1 mol/l NO₃^- with an ionic sensitivity of 58 ± 2mV/pNO₃. The detection limit was found to be 1 × 10^-5 mol/l of nitrate ions and the working pH interval of the sensor is 2.0-11 for 10^-2 mol/l NO₃^-. The sensor has a high selectivity for nitrate over chloride, sulphate, hydrogen phosphate and acetate ions with selectivity coefficients, K_NO3/X, of 7 × 10^-3, 1 × 10^-3, 2 × 10^-4 and 5 × 10^-3, respectively, and a response time of about 1 min. The SO₄-LAPS with polymeric membrane containing neutral sulphate ionophore demonstrates a sensitivity of 26 ± 1 mV/pSO₄ in a concentration range of 3 × 10^-6 to 1 × 10^-2mol/l with a reasonable selectivity over chloride, hydrogen carbonate and hydrogen phosphate ions. Selectivity coefficients, K_SO4/X, were found to be 0.6, 0.15 and 0.03, respectively.