A processing apparatus includes a powder material supply portion that supplies a powder material containing a first particle group consisting of a plurality of first particles, and a second particle group consisting of a plurality of second particles and having an average particle diameter larger than that of the first particle group, to a fiber-containing material containing a fiber during or after defibrating, and a powder material removing portion that removes at least a portion of the powder material from the fiber-containing material supplied with the powder material. It is preferable that the processing apparatus include a defibrating portion that defibrates the fiber-containing material on an upstream side of the powder material supply portion.