Provided is an integrated gas panel apparatus which has excellent responsiveness, stabilizes gas concentration, and furthermore, can keep a conventional panel shape as it is. A panel body (2) comprises at least a main flow channel block body (32) for forming a main flow channel (R2), and a branch flow channel block body (31) for forming a branch flow channel (R1). The branch flow channel block bodies (31) are arranged on the both right and left sides to face each other by having the main flow channel block body (32) at the center.