To provide a turn signal switch capable of improving operability when an operation knob is pressed in, and further smoothly and certainly cancelling a winker.

The turn signal switch comprises a handle switch case 1, the operation knob 2 having a slide knob 2a and a push button 2b, and an interlocking member 5 having a moving contact 7 capable of contacting/separating to/from a fixed contact 8 by the operation of the operation knob 2. By the sliding operation of the slide knob 2a, the moving contact 7 and the fixed contact 8 are contacted to blink the winker on a required side arranged in a vehicle. By the pressing-in operation of the push button 2b, the moving contact 7 and the fixed contact 8 are separated to cancel the blinking of the winker. The turn signal switch is equipped with a fitting hole 6a in which a tip end portion of a shaft member 11 is fitted when the push button 2b is pressed in.