To provide a manually operated device for valve driving which has a lock mechanism capable of preventing an erroneous operation or an operation due to mischief by reliably holding a locked state of a valve drive operation mechanism, and reliably locking with a simple structure by simply mounting several kinds of lock members.

In the manually operated device for valve driving, a handle 24 for manual operation installed in a rotary valve 21 is rotated via a stem 23. A lever 25 having an engagement unit 29 for opening degree fixation at the tip and a holding portion 32 at the rear end is rotatably installed in the handle 24 via an axial support portion 28. A projection 35 is installed at a rear end side separated from the axial support portion 28 by a predetermined distance in an open region 39 of the rear end side of the axial support section 28, the handle 24, the lever 25. A binding ring 41 of a locking member 40 is inserted into a space region 37 defined and formed by the axial support section 28, the handle 24, the lever 25, and the projection 35, so that the engagement unit 29 for opening degree fixation of the lever 25 is held in a locked state.