Abstract: A compact automatic signal cancelling apparatus for a direction indicator mounted on a motorcycle, engine driven bicycle or like vehicle is housed in a cylindrical member which is fixedly secured to the handlebar. A variable resistor is incorporated in the apparatus for detecting an angle of turning movement of the handlebar and its rotary shaft is connected to the body or frame of the motorcycle which serves as a reference point for the apparatus. As the handlebar is turned by the driver on the motorcycle, the apparatus in the cylindrical member is rotated while the rotary shaft of the variable resistor is kept immobable. The angle of turning movement of the handlebar is detected by the change in resistance value of the variable resistor, which is transmitted to a control circuit. The control circuit automatically turns on or off the signal on the direction indicator in response to detection of the change in resisting value of the variable resistance.