A gas sensor 10 includes a tubular protective cover 30 having an element chamber 37 therein and configured to allow a measured gas to flow from the outside into the element chamber 37; and a long sensor element 20 including a detecting portion 23 located in the element chamber 37 and configured to detect a specified gas concentration in the measured gas. An inclination angle θt of an axial direction of the sensor element 20 (i.e., a direction parallel to an element axis A1) in the element chamber 37 with respect to an axial direction of the protective cover 30 (i.e., a direction parallel to a cover axis A2) is 1° or greater.