To provide a crucible protective sheet which improves workability by preventing damage and inclination of an internal crucible and can prevent SiC formation and thickness reduction of an exterior crucible, and can prevent deterioration of product quality by maintaining heat conductivity to such a degree that heat is conducted uniformly to the internal crucible from the external crucible and maintaining gas shielding even if compressibility is high.

The crucible 1 comprises an internal crucible 2, an external crucible 3, and a sheet 4 composed of exfoliated graphite which is disposed between the crucibles 2 and 3. The sheet has heat conductivity in the plane direction of 120 W/(mK) or more, gas permeability of less than 1.010-4 cm2/s, and compressibility of 20% or more when compressed with pressure of 34.3 MPa in the thickness direction.