The present invention provides a working machine that makes it possible to alert its operator to cautions properly without obstructing the view of the operator. The working machine includes a cab for its operator to ride in, a projection device that projects image light to form an image of cautions to an operator who operates the working machine, a display unit that displays image light projected by the projection device, state detection element to detect a state of the working machine, and a controller that controls the projection device so that a manner of displaying the cautions on the display unit will change depending on the state of the working machine detected by the state detection element.