An illumination device can include a light source; and a light guiding lens for receiving light from the light source. The light guiding lens includes a light emission portion that extends in a predetermined direction and has a main surface with reflecting cuts, and a light guiding portion provided to the light emission portion at an end portion thereof in the predetermined direction. The light guiding portion is configured to project more than the light emission portion in a thickness direction of the light emission portion and extend along the end portion of the light emission portion. The light source is disposed to face to an end face of the light guiding portion in an extending direction of the light guiding portion, the end face projecting more than the light emission portion. An end face of the light guiding portion has reflecting cuts arranged in the extending direction.