The present invention discloses an improved operating fluid reservoir having a venting and/or air admission valve. The operating fluid reservoir is characterized in that a valve housing is formed integrally with an operating fluid reservoir wall. A vent opening, via which a valve housing interior is in fluid communication with a vent line, is embodied as a through opening through the operating fluid reservoir wall. A valve body, which is arranged in the valve housing interior, can be introduced into the valve housing interior via an introduction opening in the valve housing. The valve body comprises a holding device, by means of which the valve body is held movably in the valve housing.