Gas sensor

A gas sensor comprising:

• a plate-shaped sensor element extending in an axial-line direction and having an electrode pad at a main surface on a rear end side thereof;
• a metal terminal extending in the axial-line direction and electrically connected to the electrode pad;
• a separator having a storage portion which penetrates in the axial-line direction and in which the rear end side of the sensor element and the metal terminal are stored, thus retaining the metal terminal;
• and
• a grommet located on a rear end side relative to the separator, wherein
• the storage portion has a taper surface whose diameter expands toward a direction perpendicular to the main surface as approaching a rearward-facing surface of the separator,
• the grommet has a protrusion on a front end side, and a front end of the protrusion is fitted into a rear end side relative to a front end of the taper surface, along the axial-line direction, and
• the metal terminal contacts with the protrusion.