Membrane switches are manufactured by electrically conductive pastes consisting of 55 to 65% by weight of metal powder in the shape of flake (silver, aluminum, copper or the alloy thereof), 35 to 60% by weight of an organic solvent at high boiling point, 5 to 15% by weight of organic thermal plastic, including mainly saturation polyester polymer, and 0.5 to 5% by weight of additives, including trietheanolamine, adhesion promoter, defoamer, leveling agent, thixotropic agent etc. The silver paste is of excellent adhesion on ITO film or ITO glass, delivers conductivity high up to 20 mΩ / □ with less than 65% by weight of silver, and passes test under the conditions (85□, 85% RH, 1000 hours).