A roaster for roasting articles includes a containing device, an air supplying device, a first separating device, and a collector device. The containing device defines a roasting chamber. The air supplying device generates a heated air stream that flows into the roasting chamber. The first separating device has a shell unit disposed above the containing device, and a first separating member disposed in the shell unit and configured such that impurities which are carried along with the heated air stream are filtered out from the heated air stream. The collector device is connected to the shell unit for collecting the impurities filtered out from the heated air stream.