A light guide comprising: a base that has a first reflecting surface and a second reflecting surface and that propagates incident video light (L0) while totally reflecting the video light (L0) by the first reflecting surface and the second reflecting surface ; and a plurality of half mirrors , each of which has a first surface and a second surface on a back side of the first surface and is configured to include a dielectric multi-layer film , wherein the plurality of half mirrors are disposed in the base such that the half mirrors are spaced from each other by being tilted with respect to the first reflecting surface and the second reflecting surface , the base and the plurality of half mirrors are configured such that the video light (L0) made incident into the base is incident on each of the first surface and the second surface of at least one of the plurality of half mirrors one or more times, characterised in that : (i) refractive indices of two outermost layers of the dielectric multi-layer film on a first surface side and a second surface side are 0.90n to 1.15n in a case in which a refractive index of the base is n; and (ii) the half mirror has an average reflectivity of 2% to 4% with respect to light with a wavelength of 400 nm to 700 nm that is incident at an incidence angle of 5° to 35°, and has an average reflectivity of 10% or less with respect to the light incident at an incidence angle of 55° to 85°, wherein the video light (L0) is partially reflected by each of the plurality of half mirrors disposed in the base and emitted from the base as emitted light (L1) to make a user visually recognize the video. a base that has a first reflecting surface and a second reflecting surface and that propagates incident video light (L0) while totally reflecting the video light (L0) by the first reflecting surface and the second reflecting surface ; and a plurality of half mirrors , each of which has a first surface and a second surface on a back side of the first surface and is configured to include a dielectric multi-layer film , wherein the plurality of half mirrors are disposed in the base such that the half mirrors are spaced from each other by being tilted with respect to the first reflecting surface and the second reflecting surface , the base and the plurality of half mirrors are configured such that the video light (L0) made incident into the base is incident on each of the first surface and the second surface of at least one of the plurality of half mirrors one or more times, characterised in that : (i) refractive indices of two outermost layers of the dielectric multi-layer film on a first surface side and a second surface side are 0.90n to 1.15n in a case in which a refractive index of the base is n; and (ii) the half mirror has an average reflectivity of 2% to 4% with respect to light with a wavelength of 400 nm to 700 nm that is incident at an incidence angle of 5° to 35°, and has an average reflectivity of 10% or less with respect to the light incident at an incidence angle of 55° to 85°, wherein the video light (L0) is partially reflected by each of the plurality of half mirrors disposed in the base and emitted from the base as emitted light (L1) to make a user visually recognize the video. (i) refractive indices of two outermost layers of the dielectric multi-layer film on a first surface side and a second surface side are 0.90n to 1.15n in a case in which a refractive index of the base is n; and (ii) the half mirror has an average reflectivity of 2% to 4% with respect to light with a wavelength of 400 nm to 700 nm that is incident at an incidence angle of 5° to 35°, and has an average reflectivity of 10% or less with respect to the light incident at an incidence angle of 55° to 85°, wherein the video light (L0) is partially reflected by each of the plurality of half mirrors disposed in the base and emitted from the base as emitted light (L1) to make a user visually recognize the video. <EOS>