A light-guiding device used in a display device includes a plurality of first half mirrors between a first light-guiding body and a second light-guiding body. Each of the first half mirrors is formed on a first surface extending along a first direction of the first surface and a second surface extending along a second direction in the first light-guiding body. The first light-guiding body includes a third surface overlapping the second surface in a direction along a third direction in which two first surfaces located on both sides of the second surface do not overlap each other between the first surface and the second surface. The third surface extends in a direction different from the first direction.