Abstract: A plasma generating apparatus is provided which uses slipping surface discharge and microwave to generate a large quantity of plasma in a different gases or gaseous mixtures (including electro-negative gases) in a wide range of gas pressure (from a deep vacuum up to atmospheric pressure). The plasma generating apparatus includes high voltage pulse means for generating a high voltage pulse, plasma generating means based on the slipping surface discharge which excites as the high voltage pulse generated by high voltage pulse generating means, is supplied, microwave generating means for generating a microwave radiation for producing plasma, a chamber in which the plasma generating means are placed, and the plasma collects, the chamber receiving the microwave radiation from the microwave generating means, and a gas inlet through which a specific gas flows into the chamber, to generate a large quantity of plasma according to the plasma generating means and microwave generating means.