PURPOSE: To easily change a pitch of a propeller by assembling an adjusting device for a changeable pitch propeller in a propeller hub, and operating the adjusting member by a hand-operated handle.
CONSTITUTION: On the downstream side 10 of a variable pitch propeller, on a hub 11 part of the propeller, an adjusting device having a handle 15 protruded from the hub 11 is fixed. The handle 5 is pulled by spring force to a spindle nut 45. As the spindle nut 45 to adjust an inclination angle of a propeller blade 25 moves in an axial line direction, a pin 47 of the handle 15 gets apart from the spindle nut 45 to be returned to a mating flange 40 to set the nut 45 freely rotatable. As the spindle nut 45 is rotated, the nut 45, a flange 40, and a push rod 33 simultaneously slide to provide rotation to an adjusting plate 27 and the propeller blade 25, so a pitch is changed. The adjusting device is then fixed again by the handle 15.