A large-sized plasma generator is suited to various surface shapes and has a longer service life and improved energy conservation. An example of the plasma generator (1-1) has a dielectric layer (3), first and second electrodes (4, 5) that are formed within the dielectric layer, an alternating-current power supply (6), and a first metal layer (7). The dielectric layer (3) is composed of polymer resin layers (31, 32) that are formed of a polyimide resin. The electrodes are arranged side by side within the dielectric layer. The first metal layer is formed of a metal having a sterilization effect, and has a plurality of pores (71) in the surface. The first metal layer spans between supporting parts (33, 34) of the polymer resin layer (32), and faces the whole of the electrodes. A gap (S) is formed between the first metal layer and the polymer resin layer.