In an illumination device (4) including light-emitting diode (light-emitting element) (18) and LED substrate (light source substrate) (8) having a mounting surface on which the light-emitting diode (18) is mounted, a row of light-emitting diode including the plural light-emitting diodes (18) arranged along a predetermined direction is placed on the mounting surface of the LED substrate (8). Furthermore, the plural LED substrates (8) are provided in a state where adjacent LED substrates (8) are connected electrically to each other.