To prevent the surface of a heated polycrystalline silicon rod from getting covered by a steam film, and to form cracks surely by cooling promptly the polycrystalline silicon rod.

The apparatus heats the polycrystalline silicon rod R in a state of being mounted on a support rack 2, thereafter immerses in cooling water W in a tank 5 to quench, and generates cracks to crush. The support rack 2 is supported reciprocatingly between the inside and the outside of the tank 5, and at the same time, has a jetting apparatus 25 jetting the cooling water toward the polycrystalline silicon rod R in the state of being immersed in the tank 5 together with the support rack 2.