A method for producing cubic boron nitride includes maintaining hexagonal boron nitride in the presence of a catalyst substance under conditions where cubic boron nitride remains thermodynamically stable to thereby transform hexagonal boron nitride into cubic boron nitride, wherein the catalyst substance contains LiMBN₂, in which M represents Ca, Sr, Ba, Ra, Be, or Mg, and at least one species selected from the group consisting of alkali metals, alkaline earth metals, nitrides thereof and boronitrides thereof. Any one of the LiMBN₂, alkali metals, alkaline earth metals, nitrides thereof and boronitrides thereof has an oxygen content of 1% or less. As a result, the percent transformation into cubic boron nitride can be considerably enhanced, and the cubic boron nitride obtained exhibits high mechanical strength.