An illumination device has at least one fluorescent tube, a lower frame supporting the fluorescent tube, a light diffusion plate which opposes the lower frame with the fluorescent tube being interposed therebetween for forward diffusion of output light of the fluorescent tube, a reflection sheet disposed along the fluorescent tube side of the lower frame for reflecting the fluorescent light toward the light diffuser plate, and an upside reflector covering an electrode of the fluorescent tube for reflecting the light toward the light diffuser. When letting a direction along a length of the fluorescent tube be a horizontal direction, a distance between the fluorescent tube and the reflection sheet at at least one of nearby portions of right and left ends of the illuminator is greater than such distance at a central portion thereof. A liquid crystal display (LCD) apparatus using the illuminator is also disclosed.