An illumination device and display device using it display motion pictures without a blur and make a light utilizing efficiency of a backlight improved. An illumination device having a light pipe of a substantially parallel flat-form sheet, whose one surface is an outgoing light surface and a light source unit is placed at one side and both side edges, is equipped with a light axis of lights after having entered the light pipe from the light source unit being unparallel to the outgoing light surface of the light pipe, and a reflection body unit consisting of plural unit reflection bodies divided into m in a vertical direction of the light source unit at an opposite side surface of the outgoing light surface of the light pipe, wherein the reflection body unit can contact and separate from the opposite side surface the outgoing light surface of the light pipe for every unit reflection bodies.