A permanent-magnet motor composed of an irony barrel, a magnet set, a magnet holder, and a rotor. The irony barrel includes a thin body. The magnet set includes a plurality of magnets. The magnet holder is received inside the irony holder and includes a plurality of retaining pieces located at an internal edge thereof for holding the magnet set. The rotor includes a rotor silicon steel sheet, a deflector, a rotary shaft, a front bearing, and a rear bearing, being inserted inside the magnet set. In light of this, the magnet set can not only maintain the same thickness as that of the conventional irony barrel but also reduce the thickness of the front and rear parts of the irony barrel, so that the production cost of the irony material can be effectively decreased. Besides, the magnet holder can definitely space and position the magnets to enhance the assembly efficiency.