This master controller is provided with: a main handle (1); a handle drum (9); a reversing handle (6); a locking collar (10); a first locking cam (3) that has an outer peripheral surface for locking the reverse handle (6) in a neutral position when an operation key (12) is in a locked position; a second locking cam (5) that rotates integrally with the reversing handle (6) and has an outer peripheral surface for locking the reversing handle (6) and the main handle (1) in neutral positions when the operation key (12) is in the locked position, and for locking, when the reversing handle (6) is moved to a forward position or a reverse position, the reversing handle (6) in the forward position or the reverse position and unlocking the main handle (1) at the same time; and a rod-holding section (11) that holds a rod (7) in a slidable manner between the locking collar (10) and the second locking cam (5), said rod extending parallel to a spindle (9a) of the handle drum (9) from one end surface of the locking collar (10) toward the outer peripheral surface of the second locking cam (5).