A chassis assembly comprises a chassis 14 and lamp clips 18. The chassis 14 has mounting holes 33 to 35. Each lamp clip 18 includes a main body 27 to be mounted to the chassis 14, a lamp gripping portions 28 provided on the main body 27 so as to grip cold cathode tubes 17, and mounting portions 30 to 32 protruding from the main body 27 toward the chassis 14 side. The mounting portions 30 to 32 are to be inserted in the respective mounting holes 33 to 25. Rims of the mounting holes 33 to 35 are sandwiched between the main body 27 and the respective mounting portions 30 to 32. Three mounting portions 30 to 32 and three mounting holes 33 to 35 are provided in relative positions so as to restrict mounting of the lamp clip 18 to the chassis 14 in an orientation other than a predefined orientation.