PROBLEM TO BE SOLVED: To enable a person inside a vehicle to reliably recognize display directed to a target outside the vehicle.SOLUTION: There is provided a display system 1000 in a vehicle comprising: a HUD device 500 that performs display on a glass of the vehicle; an environment information acquisition part 402 that acquires the position of a target person present outside the vehicle; and a HUD control part 414 that controls the HUD device 500 to invert display directed to the target person according to the position of the target person. This configuration enables a person inside the vehicle to reliably recognize the display directed to the target outside the vehicle.SELECTED DRAWING: Figure 1