Pressure vessel

特許 係属中 PROBLEM TO BE SOLVED: To provide a pressure vessel for producing a crystal of a group 13 element nitride compound, in which a material for a shield part is strengthened and thereby which can be used repeatedly with an increased frequency. ; SOLUTION: The pressure vessel is used for producing a crystal of a group 13 element nitride compound in an ammonia atmosphere having a temperature of 600-850[deg.]C and pressure of 30-250 MPa.