Abstract: The ECR plasma enhanced deposition was used to grow GaN film. A high local concentration of reactant was created by a gas-distributor. The ECR condition was diagnosed. The ion density m, electron temperature T_e and ion current density J_i were measured by Langmuir probe and Faraday cup. The growth condition was optimized in the light of these parameters. The wurtzite GaN with fine optical property was grown in this condition. The results of AES and XPS showed the film is grown without excess N vacancy and/or Ga co-deposition. The growth rate, 1m/hr, was achieved which was one-magnitude-order larger than usual ECR deposition.