To provide a gas sensor capable of magnifying a response speed and detection limit low concentration, and to provide a manufacturing method therefor.

The gas sensor is equipped with an insulating base material 1; the positive electrode layer 11 and negative electrode layer 12 positioned on the base material in a spaced-apart state, and the response layer 3 positioned over the positive electrode layer, wherein the negative electrode layer and the thickness of the response layer 3 is 1.2 times or below that of the positive electrode layer or negative electrode layer and 30 m or below.