A spacer for an electrolyzer cell of substantially annular shape comprises: a peripheral part having two parallel principal faces opposite each other, the distance separating the two principal faces defining a thickness of the spacer, and an internal part having a thickness strictly less than the thickness of the spacer, the peripheral part and the internal part being in one piece and connected to each other forming an internal annular shoulder so that the internal part has a substantially annular intermediate face extending in a plane parallel to the two principal faces of the peripheral part and situated between the two principal faces.