Manual diaphragm valve

The purpose of the present invention is to provide a manual diaphragm valve in which the opening/closing range of a valve body can be set while maintaining compactness with a simple structure, the flow rate during full opening can be sufficiently ensured without being affected by individual differences in the internal shape of the valve, and the flow rate during full opening can be arbitrarily adjusted. The valve body (1) is provided with a valve body (12) fitted inside the main body (10), and a main shaft (13) which is screwed into the main body (10) so as to be able to move up and down and which brings the valve body (12) into contact with and separates from the valve seat (14), a handle (2) which manually rotates the main shaft (13) is attached above the valve body (1), and a fully open position adjustment mechanism (20) is provided near the upper part of the valve body (1). The fully-open position adjustment mechanism (20) limits rotation of the handle (2) at the time of fully opening the valve opening op