A gas sensor includes a sensor element, a tubular body made of metal, and a sealing material. The sensor element has a surface. The tubular body has a through hole which is formed along the axial direction and through which the sensor element is inserted. The sealing material is placed inside the through hole and between the inner peripheral surface of the through hole and the sensor element. The sealing material covers a part of the surface of the sensor element. When the sensor element is viewed in cross section from a second direction perpendicular to a first direction corresponding to the longitudinal direction of the sensor element, the sealing material forms a first inclination angle of not less than 10° and not more than 80° with respect to the surface.