PROBLEM TO BE SOLVED: To provide a production method of a nitride semiconductor crystal of a group 13 metal in the periodic table, capable of producing a high-quality bulk crystal by suppressing generation of a polycrystal.SOLUTION: A production method of a nitride semiconductor crystal of a group 13 metal in the periodic table includes: a heating step for heating a reservoir 4 for storing a raw material of a group 13 metal in the periodic table at a temperature of 150°C or higher; and a growth step for growing a nitride semiconductor crystal of the group 13 metal in the periodic table on a ground substrate 11 by introducing halogen-containing gas into the reservoir 4, and by heating at least the reservoir 4 at the temperature of 150°C or higher.
