A transparent touch panel substrate comprising a transparent substrate and deposited thereon a transparent conductive metal oxide film which contains zinc, indium, and tin as metallic elements and is soluble in acids. The transparent conductive metal oxide film preferably contains zinc in an amount of from 40 to 65 atomic % based on all metals and contains indium in an amount of from 0.25 to 1.3 times the amount of tin on an atomic basis. The film preferably has a thickness of from 100 to 160 nm. Unlike the conventional substrate for resistive film type transparent touch panels which comprises a glass plate coated with a transparent conductive ITO film, the touch panel substrate of the invention combines three properties: high light transmittance; ease of processing in forming a transparent electrode by acid etching; and the transparent conductive film has a moderate sheet resistance of from 500 to 5,000&OHgr;. It therefore realizes a touch panel which combines the three functions of having satisfactory display quality, being of the power-saving type, and enabling touch switch operations to be conducted without fail.