Abstract: A plurality of holders, each capable of holding a rod of raw material, and a single handler are equipped within a chamber which is adapted to be evacuated. An operator positions one of the holders at a location where it is opposite to a rotary shaft capable of driving the rod of raw material for rotation at a high speed. The operator then secures the rod held by the holder to the free end of the rotary shaft by handling the holder. A rod of raw material which has become consumed by granulation is separated from the rotary shaft by the handler which is operated by the operator. A fresh holder is then positioned at a location where it is opposite to the rotary shaft, and a rod of raw material which is held thereby is then secured to the rotary shaft.