Abstract: To provide a method and apparatus for production of a nitrogen compound film by a plasma, wherein the method and apparatus are suitable for area enlargement by a process at a higher pressure with lower power consumption, without applying a voltage to a base material, and without using a large chamber. In nitrogen compound production for producing a nitrogen compound by generating a microwave plasma, in a step of jetting a material gas containing a nitrogen-based gas onto a surface of a base material from a nozzle under flow rate control while applying a microwave to the material gas to thereby irradiate the surface of the base material with a plasma containing nitrogen-based reactive species generated from the material gas, the pressure is set higher than a pressure at which the mean free path of ions in the plasma is shorter than the Debye length.