An apparatus for feeding and dosing powder includes a powder storage container, an oscillating feeder with feeder with adjustable feeding rate for dispensing the powder to a powder outlet, a conduit arrangement for feeding the powder dispensed from the oscillating feeder in a feeding gas as a powder-gas mixture and for supplying the powder-gas mixture to a powder processor, wherein a decoupler is provided in the conduit arrangement to extract a defined proportion of the powder from the powder-gas mixture, a powder quantity measuring arrangement for detecting the decoupled powder quantity and for providing a powder quantity information signal, wherein the extracted powder quantity has a predetermined ratio to the fed powder quantity of the oscillating feeder, and controller configured to adjust the adjustable feeding rate of the oscillating feeder to a predetermined set value based on the powder quantity information signal provided.