Method for producing ultraviolet light hexagonal boron nitride crystal

And to provide a method also conveniently synthesized under normal pressure with high purity hBN crystals to rigid substrates. Method for producing a hexagonal boron nitride crystal according to the present invention, the step of heating comprising the steps of preparing a mixture comprising a metal solvent comprising a transition metal and boron nitride material, and contacting the sapphire substrate to the mixture and the mixture When, characterized by comprising a melt obtained by heating and a step of recrystallizing at normal pressure. Further, without using the sapphire substrate, as the metal solvent, Fe, Ni, Co, and a transition metal selected from the group consisting of, Cr, at least one selected from the group consisting of TiN and V characterized by using those containing a that substance.