To provide an illumination device that can perform display having improved designability where one who sees the display can enjoy beauty by irradiating a light-transmitting member with light without, for example, performing coating to the light-transmitting member, can change the display depending on the presence or absence of irradiation of light, and can transmit larger information content.

For the light-transmitting member 1000, only light impinging on a design surface 1220 from among light emitted from a light source advances inside the light-transmitting member 1000 and maintains a prescribed color, and reaches a table surface 1110 at an incidence angle smaller than a critical angle. Alternatively, light impinging on the design surface 1220 has intensity larger than that impinging on a surrounding surface 1210 and reaches a table surface 1110 at an incidence angle smaller than the critical angle. Alternatively, light impinging on the design surface 1220 does not reach the table surface 1110 and a shape of the design surface 1220 in a bottom view is projected to the table surface 1110.