An object of the present invention is to reduce the tendency that local deformation occurs in an extending member in a backlight unit. A backlight unit 12 of the present invention includes LEDs 17 as light sources, a chassis 14 that stores the LEDs 17, a reflection sheet 21 and an LED substrate 18 as extending members extending along an inner surface of the chassis 14 and a holding member 20 that holds the reflection sheet 21 and the LED substrate 18 with the chassis 14 such that the reflection sheet 21 and the LED substrate 18 are sandwiched between the holding member 20 and the chassis 14. The holding member 20 is fixed to the chassis 14. The holding member 20 includes contact portions 26 that protrude toward the reflection sheet 21 and the LED substrate 18. The contact portions 26 are in contact with the reflection sheet 21 and the LED substrate 18.