Abstract: Dust recovery apparatus is disclosed which recovers air-entrained dust in a high state of purity. The apparatus comprises a housing capable of sustaining at least slight positive pressure and suitable for accommodating powder processing machinery, an air supply system for passing air at a predetermined rate and at a slight positive pressure to the housing, a collector which collects dust entrained in air leaving the housing and an air-flow rate sensor which detects air-flow rate in the apparatus and activates valves for stopping air passing to the collector when the air-flow rate falls outside a predetermined range.