The present disclosure provides a composite electrode, an acoustic sensor using the composite electrode, and a manufacturing method of the composite electrode. The composite electrode includes a conductive layer, and a semiconductor high-molecular polymer layer formed on the conductive layer. The semiconductor high-molecular polymer layer has a three-dimensional mesh structure. The acoustic sensor includes a base; the above-mentioned composite electrode formed on the base; an organic layer formed on the composite electrode; and a top electrode formed on the organic layer.