WAFER SHIPPING BOX

PROBLEM TO BE SOLVED: To automatically cancel pressure difference between the inside and the outside of a box, to prevent box deformation caused by the pressure difference and contaminants sticking to the side of case, to make the box advantageous in terms of cost, to recycle the box and to hardly transfer impulse to a wafer as well. SOLUTION: When external atmospheric pressure changes and an inner/outer pressure difference occurs in a sealed wafer shipping box 10, air flows from the side of higher pressure to the side of lower pressure between the inside and outside of this box via a filter 20. Therefore, this pressure difference is automatically canceled. As a result, the damage of a wafer case 11 or silicon wafer W due to box deformation caused by the pressure difference can be prevented. Contaminants are filtered by the filter 20 and will not infiltrate the inside of the box 11. Furthermore, since a structure is simple, these effects can be provided comparatively at low cost.