An information processing apparatus includes a display unit having a first reflective plate and a second reflective plate forming a reflective-plate unit, and a third reflective plate. The first reflective plate is bonded to an external frame, and the second reflective plate is connected to a reflective-plate hinge. In addition, the third reflective plate is pivotally connected-to the reflective-plate hinge, and a diffusion plate is bonded to the third reflective plate. Light emitted from a cold-cathode fluorescent lamp is guided by an optical waveguide and illuminates the entire surface of a liquid crystal panel. In addition, a part of the light is reflected by the second reflective plate, is incident on the diffusion plate bonded to the third reflective plate, is efficiently diffused by the diffusion plate, and uniformly illuminates an operation unit such as a keyboard.