Gas sensor having improved structure of electric connector

A gas sensor comprising:

• a hollow cylindrical housing;
• a sensor element made of a laminated plate which includes a sensing portion and a base portion opposite the sensing portion and which has an array of electrode terminals formed on each of opposed surfaces of the base portion, said sensor element being retained at a sensing portion thereof by an insulation porcelain within said housing;
• a cover covering the base portion of the sensor element;
• a connector disposed within said cover, said connector having two terminal arrays each made up of four terminals making electric connections to the electrode terminals of said sensor element, wherein each array is connected electrically to one of the arrays of electrode terminals of said sensor element, each of the terminals including a contact which is elastically deformable at least in a direction substantially perpendicular to the opposed surfaces of said sensor element to establish a firm electric connection to one of the electrode terminals of said sensor element, wherein said connector includes insulating members;
• and
• a retaining spring member disposed within said cover to elastically retain each of the arrays of terminals of said connector through one of the insulating members so as to urge the terminals of said connector into constant contact with the electrode terminals of said sensor element.