Substrate processing apparatus

A substrate processing apparatus is capable of providing a comprehensive uniform treatment on a substrate without being current in a situation where the current is stored in a housing container. According to the present invention, while a substrate W is being moved through a roller 15, a plasma gas is discharged above the substrate W from a nozzle 20 for removing organic matters adhered on the substrate W, where two lateral diffusion baffles 30 are mounted near the bottom of the nozzle 20 and parallel to the advancement direction of the substrate W, and a lower diffusion baffle 31 is mounted below the nozzle 20. Thus, the current FL12 in a processing chamber 10 can be adjusted by the installation of the lateral diffusion baffles 30 and the lower diffusion baffle 31, whereby the plasma gas FL11 is uniform at the edges and the center part of the substrate W, thereby providing a uniform removal of organic matters from the whole substrate W.