The mixing device for mixing a powder with a pressurized gas, comprising a mixing chamber (20) with an inlet area (22), which has at least one inlet opening (24), by way of which powder and/or pressurized gas and/or a mixture thereof may be introduced into the mixing chamber (20), and at least one outlet area (26), which is designed for withdrawing from the mixing chamber (20) a main flow (HR) of a gas or powder or a powder and gas mixture directed along the mixing chamber (20) which essentially extends from the inlet area (22) to the outlet area (26), characterized in that a regulating device (10) is arranged along and/or in continuation of the main flow (HR), regulating the main flow (HR) of the gas or powder or powder and gas mixture.