A joystick includes a body, a feature identifier and a processor. The body has a lateral portion and a bottom portion connected with each other. The bottom portion is adapted to be pressed, and the lateral portion whereon an identification element is disposed is adapted to support the bottom portion. The feature identifier is disposed under the body and adapted to acquire an identification result about the body. The processor is electrically connected with the feature identifier and adapted to analyze state of the identification element within the identification result for generating a control signal. The feature identifier is an image sensor, and accordingly the identification result is a frame captured by the image sensor.