A liquid crystal display device includes a liquid crystal panel and an illumination device. The illumination device has a light guide plate and at least one spot light source on at least one side surface of the light guide plate. The light guide plate includes a large number of upper-surface arcuate cross-sectional grooves in a direction orthogonal to the one side surface on a surface thereof which faces the liquid crystal panel, and a large number of light-incident-surface arcuate cross-sectional grooves are formed in a thickness direction of the light guide plate on at least a portion of the one side surface which faces a position at which the spot light source is arranged. A relationship is provided between a contact angle Oa of the upper-surface arcuate cross-sectional grooves and a contact angle Ea of the light-incident-surface arcuate cross-sectional grooves.