A display device includes: first setting means for setting a first operation amount to be performed by an occupant so as to increase an output in a state in which a vehicle speed is less than a predetermined threshold; second setting means for setting a second operation amount to be performed by the occupant such that an operation state of the vehicle can be shifted to a desired state in which optimal instantaneous fuel consumption is realized, by decreasing the output in a state in which the vehicle speed is equal to or greater than the predetermined threshold; and display means for displaying, on a display unit, at least one of the first operation amount and the second operation amount, and a present operation amount which is an operation amount performed at present by the occupant.