To provide the channel box and manufacturing method thereof, wherein the overall corrosion-resistance property covering nodular corrosion is enhanced in consideration of the state of the cooling water in a reactor core.

In a channel box 1a of the fuel for a light water reactor in a tube body formed of zirconium-based alloy, the diameter of the deposited particle of the alloy component of a boiling region 12 of the tube body is set at 0.2μm or less. Furthermore, the grain diameter of the deposited material in a non-boiled region 13 of the tube body is set at 0.2μm or more. Since the grain diameter of the deposited material in the boiling region 12 is small, the nodular-corrosion resistance is excellent. Since the grain diameter of the deposited material in the non-boilded region 13 is rough, the characteristics excellent in uniformity resistance is displayed. Thus, the overall corrosion resistance can be enhanced.