An auto-dosing device for substrate treatment composition applicable to a substrate treatment machine, e.g., a washing machine, the auto-dosing device comprising: a) a main body, b) a base, attached to the main body, configured to support a container of the substrate treatment composition in an inverted position, wherein the base comprises: i) a receiving body extending in a longitudinal direction to receive the neck of the container and having an open end with an annular rim for supporting the container, and a closed bottom end opposite to the open end in the longitudinal direction and having outlets through which the substrate treatment composition can flow; ii) a penetrating member arranged in the receiving body for opening the container; and iii) a ventilation feature configured to fluidly communicate an interior of the container with outside air through the main body when the container is supported on the base for air to flow into the container from outside so that the substrate treatment composition in the container can flow out, and wherein the main body comprises: a reservoir supporting and fluidly connected with the base to receive the substrate treatment composition from the container via the base; and a delivering assembly configured to controllably deliver the substrate treatment composition from the reservoir to a substrate treatment machine; wherein the penetrating member is hollow with a basal end opened to the interior of the reservoir through a bottom surface at the bottom end of the receiving body and a closed distal end, and at least one venting aperture is defined in a side wall of the penetrating member as part of the ventilation feature, and the venting aperture is closer to the open end of the receiving body than the outlets in the longitudinal direction; characterised in that, with the ventilation feature of the base and the reservoir, air flows from outside into the container through air inlets 28, the interior of the reservoir, and an air passage in the penetrating member in this order; and wherein, with balance of air pressure inside and outside the container, the substrate treatment composition therein flows into the receiving body of the base through a gap between the penetrating member and a annular portion of a cap by gravity, and then goes into the reservoir through the outlets of the base. a) a main body, b) a base, attached to the main body, configured to support a container of the substrate treatment composition in an inverted position, i) a receiving body extending in a longitudinal direction to receive the neck of the container and having an open end with an annular rim for supporting the container, and a closed bottom end opposite to the open end in the longitudinal direction and having outlets through which the substrate treatment composition can flow; ii) a penetrating member arranged in the receiving body for opening the container; and iii) a ventilation feature configured to fluidly communicate an interior of the container with outside air through the main body when the container is supported on the base for air to flow into the container from outside so that the substrate treatment composition in the container can flow out, and a reservoir supporting and fluidly connected with the base to receive the substrate treatment composition from the container via the base; and a delivering assembly configured to controllably deliver the substrate treatment composition from the reservoir to a substrate treatment machine; wherein the penetrating member is hollow with a basal end opened to the interior of the reservoir through a bottom surface at the bottom end of the receiving body and a closed distal end, and at least one venting aperture is defined in a side wall of the penetrating member as part of the ventilation feature, and the venting aperture is closer to the open end of the receiving body than the outlets in the longitudinal direction; characterised in that, with the ventilation feature of the base and the reservoir, air flows from outside into the container through air inlets 28, the interior of the reservoir, and an air passage in the penetrating member in this order; and wherein, with balance of air pressure inside and outside the container, the substrate treatment composition therein flows into the receiving body of the base through a gap between the penetrating member and a annular portion of a cap by gravity, and then goes into the reservoir through the outlets of the base.