The invention is directed to a display device for working vehicle, which is adapted so that additional information can be displayed. In the invention, display indication marks of the two types can be interchangeably displayed on a common display screen of a limited area without reducing the sizes of the individual marks, so that neither a larger size of a display device nor a drop in the visibility of the indication marks is necessary. This enables the driver to control a working machine such as a construction machine and have additional information about the construction machine without any trouble in the driving.