Abstract: A card edge connector includes an elongated housing; upper and lower stage contacts and held by the housing; and arm members for pressing, toward a connector mounting surface, a memory module to be displaced in a direction away from the connector mounting surface. Inserting an arm inserted portion of each arm member in an insertion groove of the housing allows the housing to hold each arm member freely swingable about the arm inserted portion with respect to the housing. Hemispherical projections for securing at least a predetermined amount of gap amounts of swing gaps are provided in the swing gaps and formed in the longitudinal direction of the housing between the arm member within the insertion groove and the housing.