A multiple discharge plasma apparatus is provided with a plurality of discharge apparatuses arranged on at least one of the members each of which has an electrode exposed in a combustion chamber and configures the combustion chamber; an antenna arranged on at least one of the members configuring the combustion chamber so as to radiate electromagnetic waves to the combustion chamber; an electromagnetic wave transmission path, which is arranged on at least one of the members configuring the combustion chamber, with one end connected to the antenna and the other end covered with an insulating material or a dielectric material and extending to a portion in a cylinder block or a cylinder head at a distance from the combustion chamber; and an electromagnetic wave generating apparatus which supplies the electromagnetic wave transmission path with electromagnetic waves. The multiple discharge plasma apparatus is configured such that the electrodes of a plurality of discharge apparatuses are made to discharge electricity in a compression step, and the electromagnetic waves supplied from the electromagnetic wave generating apparatus through the electromagnetic wave transmission path are radiated from the antenna.