To provide a powder treatment apparatus capable of realizing the enhancement of a product yield and a fine powder removing ratio by enhancing classification precision.

The powder treatment apparatus is provided with a dispersing rotor 2 for applying mechanical energy to the raw material charged in a treatment chamber S to obtain a treated powder, a classifying rotor 3 for passing the fine powder with a predetermined particle size or below of the raw material and the treated powder through the rotor along with an air stream from a classifying blades 3a, a fine powder discharge part 4 for sucking the fine powder in the rotor from the discharge opening 3b formed to one side surface in the cylinder axis direction of the classifying rotor 3 to discharge the same to the outside and an outlet part 5 for taking out the treated powder remaining in the treatment chamber S. The classifying rotor 3 is equipped with the cylindrical member 3c communicating with the discharge opening 3b at its base end part and extending into the rotor along the cylinder axis direction as it turns smaller in its outer diameter toward its leading end side. The fine powder is allowed to flow into the cylindrical member 3c from the opening of its leading end part to be sent to the discharge opening 3b.