We have applied the cavity type and the ECR microwave discharges to the several chemical reactions. They are Nitriding titanium and Ammonia synthesis (i), Nitriding of aluminium oxide(ii), and Deposition of carbonaceous films (iii). The results obtained are summarized.

(i) In the nitriding of titanium as well as the ammonia synthesis, the effect of driving frequency on the electric field strength in the discharge is manifested, that is, excited nitrogen atoms in the nitrogen plasma as well as large amounts of NH radicals in the nitrogen-hydrogen plasma are formed in the plasma and the reaction rates of both reactions were promoted.

(ii) In the nitriding of aluminium oxide, the specimen was dielectrically heated in the discharge and aluminium nitride was formed in the nitrogen-hydrogen plasma.

(iii) In the ECR, the plasma is confirmed by the magnetic field and the ion density increased. The ions created in the methane plasma would contribute to the deposition of unique carbonaceous films.