Device for preparing a coffee product, comprising a preparation chamber which is intended and configured to receive and collect a quantity of ground coffee in a coffee bed, and provided with pump means for carrying hot water under increased pressure to the preparation chamber, wherein the preparation chamber is provided with a water inlet for admitting water at increased temperature and pressure on a feed side of the coffee bed, wherein the preparation chamber is provided with an outlet on a discharge side beyond the coffee bed, wherein the outlet is coupled via a product conduit to an outflow at which the coffee product can be taken away, and wherein the device is provided with an electronic control system which imposes a preparation cycle each time a product is prepared, between the outlet of the preparation chamber and the outflow at which the coffee product can be taken away the product conduit comprises an adjustable valve device with an adjustable restriction, a smallest passage of which is proportionally adjustable and controlled by the control system, wherein the valve device comprises a liquid channel between a valve member and a valve housing (36, 42), wherein a flow resistance of the liquid channel is controllable by the control system through an adjustment of the valve member relative to the valve housing, characterized in that the valve housing comprises a valve cavity (421, 631) and the valve member comprises a valve body received close-fittingly in the valve cavity, wherein the liquid channel is formed between an inner wall of the receiving cavity and an outer wall of the valve body, and that the valve body is adjustable relative to the receiving cavity, and that the liquid channel extends in at least one groove (423, 623) in at least one of the inner wall of the valve cavity and the outer wall of the valve body received therein. provided with pump means for carrying hot water under increased pressure to the preparation chamber, wherein the preparation chamber is provided with a water inlet for admitting water at increased temperature and pressure on a feed side of the coffee bed, wherein the preparation chamber is provided with an outlet on a discharge side beyond the coffee bed, wherein the outlet is coupled via a product conduit to an outflow at which the coffee product can be taken away, and wherein the device is provided with an electronic control system which imposes a preparation cycle each time a product is prepared, between the outlet of the preparation chamber and the outflow at which the coffee product can be taken away the product conduit comprises an adjustable valve device with an adjustable restriction, a smallest passage of which is proportionally adjustable and controlled by the control system, wherein the valve device comprises a liquid channel between a valve member and a valve housing (36, 42), wherein a flow resistance of the liquid channel is controllable by the control system through an adjustment of the valve member relative to the valve housing, characterized in that the valve housing comprises a valve cavity (421, 631) and the valve member comprises a valve body received close-fittingly in the valve cavity, wherein the liquid channel is formed between an inner wall of the receiving cavity and an outer wall of the valve body, and that the valve body is adjustable relative to the receiving cavity, and that the liquid channel extends in at least one groove (423, 623) in at least one of the inner wall of the valve cavity and the outer wall of the valve body received therein.