To provide an anticrime thumb turn which is set up by minimizing the number of component parts including an input member and an operation obstructor on a gripping side.

The crime-preventing thumb turn is formed of: a movable seat which is arranged in a manner overlapping a front surface of a fixed seat, and has a central annular portion; a central shaft which is inserted into a fitting hole formed in the movable seat and a shaft hole formed in the fixed seat, and rotatable together with the movable seat via a plurality of operating pins; an operating lever which has a frame-shaped pressing portion fitted onto a peripheral portion of the central annular portion across an interval; and the operating pins which are installed inside the pressing portion and in continuous holes radially formed in the central annular portion and the central shaft in alignment. When the operating lever is operated, the operating pins are pressed to the pressing portion of the operating lever and simultaneously carry out linear movement, and they are positionally displaced to set the thumb turn in either a normal mode or an anticrime mode.