Gas sensor

A gas sensor comprising:

• a sensor element extending in an axial-line direction and having an electrode pad on a rear-end-side outer surface thereof;
• a metal terminal extending in the axial-line direction and electrically connected to the electrode pad via a contact portion;
• and
• a tubular separator extending in the axial-line direction and retaining a rear-end side of the metal terminal, wherein
• the metal terminal includes a stopper portion extending in a direction crossing the axial-line direction,
• the contact portion and the stopper portion are housed inside the separator, and
• where, in a pair of one of said electrode pad and one of said metal terminal connected thereto, as seen along a widthwise direction of a cross section of the sensor element that is perpendicular to the axial-line direction, an end of the one electrode pad that is closest to one inner surface of the separator is defined as a pad end, a distance between the pad end and the contact portion is defined as DA, and a distance between the one inner surface of the separator and a distal end of the stopper portion is defined as DB, DA>DB and DB>0 are satisfied.