Nitride single crystal

Patent Pending PROBLEM TO BE SOLVED: To provide a new method for producing a nitride single crystal, by which a nitride single crystal having a maximum dimension of 1 mm or more can be obtained by using spontaneous nucleation in an ammonothermal method. ; SOLUTION: The method for producing a nitride single crystal from a nitride polycrystal by an ammonothermal method is carried out by using at least one kind of nitride polycrystal as a raw material in the presence of ammonia in a supercritical or subcritical state in a corrosion-resistant autoclave and adding at least one kind of acidic mineralizer to the ammonia