To display by confining a viewing angle of a display screen that displays security information to a narrow range, thus maintaining security.

A display part 20 is provided with a dual view liquid crystal panel capable of displaying a first image having a viewing angle in the front surface direction and a second image having a viewing angle in the back surface direction at the same time. Therein, information to be assured of security is displayed on the second image. A user P standing on the front of the display device 10 visualizes a reflection part 30 by a visual line V1. The second image displayed on the display part 20 can be visualized on the reflection part 30. On the other hand, when the other person Q standing near the user P visualizes the reflection part 30 by the visual line V2, the angle (incident angle) of the visual line V2 for the reflection part 30 becomes larger and, therefore, the other person Q can not visualize the second image displayed on the display part 20.