A plasma forming apparatus is provided to adjust uniformly ion density of process gas of a plasma state by adjusting intensity and uniformity of electric field. A chamber(101) provides a predetermined space for forming a plasma state of reaction gas supplied from a gas supply unit. A substrate stage(120) is installed in the inside of the chamber and includes a lower electrode. A first upper electrode(130) is provided on an upper side of the chamber in order to form first electric field for forming the plasma state of the reaction gas. A second upper electrode(140) is installed opposite to the substrate stage in the inside of the chamber. A plurality of slits(145) are formed at the second upper electrode in order to pass partially the first electric field. The second upper electrode is used for generating second electric field for forming the plasma state of the reaction gas.
