Diaphragm Valve

A diaphragm valve comprising:

• a valve body having a flow channel where fluid flows,
• a diaphragm which opens/closes said flow channel by abutting against and separating from said flow channel,
• a bonnet which sandwiches a circumferential edge of said diaphragm between said bonnet and said valve body,
• an operation mechanism attached to said bonnet for moving said diaphragm up and down, and
• a fixing mechanism for fixing said bonnet and said valve body,
• wherein said fixing mechanism comprises a clamping member for integrally sandwiching and fixing, from both right and left sides, circumferential edges of both said bonnet and said valve body,
• wherein a circular pressing member for pressing a circumferential edge of said diaphragm from above is interposed between said diaphragm and said bonnet,
• wherein the pressing member has convex portions and concave portions,
• wherein said convex portions fit into notches provided at said circumferential edge of said diaphragm or said valve body, and
• wherein said concave portions are fitted by protrusions provided at said circumferential edge of said diaphragm or said valve body.