A backlight unit comprising: a bottom cover; a light emitting module including a plurality of light emitting elements, the light emitting module being disposed in a lower portion of an inside of the bottom cover; fixing members including: a fist fixing member; a second fixing member; a third fixing member; a fourth fixing member; wherein each of the fixing members is disposed at a different side of the bottom cover; a light guide plate disposed adjacent to the light emitting module and in front of the bottom cover; at least one optical sheet and a reflective sheet, the light guide plate being between the optical sheet and the reflective sheet; first recesses (20a; 30a; 40a) disposed at the edges of the light guide plate, the reflective sheet and the at least one optical sheet; and first protrusions disposed on the bottom cover, the first protrusions being inserted into the first recesses (20a; 30a; 40a); wherein each of the first recesses (20a; 30a; 40a) is disposed on the edges of the light guide plate, the at least one optical sheet and the reflective sheet, wherein at least one connection hole (10f, 10g) is formed in the bottom cover, and wherein the connection hole allows the fixing members to be connected to the bottom cover through connection members, wherein: the second fixing member includes a first part configured to support a display panel, second parts protruded upwardly from the first part, the second parts configured to prevent movement of the display panel, third parts and fourth parts protruded downwardly from the first part, the third parts and fourth parts separated from each other and alternately disposed to be connected to inner and outer surfaces of a side wall of the bottom cover. a bottom cover; a light emitting module including a plurality of light emitting elements, the light emitting module being disposed in a lower portion of an inside of the bottom cover; fixing members including: a fist fixing member; a second fixing member; a third fixing member; a fourth fixing member; wherein each of the fixing members is disposed at a different side of the bottom cover; a light guide plate disposed adjacent to the light emitting module and in front of the bottom cover; at least one optical sheet and a reflective sheet, the light guide plate being between the optical sheet and the reflective sheet; first recesses (20a; 30a; 40a) disposed at the edges of the light guide plate, the reflective sheet and the at least one optical sheet; and first protrusions disposed on the bottom cover, the first protrusions being inserted into the first recesses (20a; 30a; 40a); wherein each of the first recesses (20a; 30a; 40a) is disposed on the edges of the light guide plate, the at least one optical sheet and the reflective sheet, wherein at least one connection hole (10f, 10g) is formed in the bottom cover, and wherein the connection hole allows the fixing members to be connected to the bottom cover through connection members, wherein: the second fixing member includes a first part configured to support a display panel, second parts protruded upwardly from the first part, the second parts configured to prevent movement of the display panel, third parts and fourth parts protruded downwardly from the first part, the third parts and fourth parts separated from each other and alternately disposed to be connected to inner and outer surfaces of a side wall of the bottom cover. a fist fixing member; a second fixing member; a third fixing member; a fourth fixing member; wherein each of the fixing members is disposed at a different side of the bottom cover; a light guide plate disposed adjacent to the light emitting module and in front of the bottom cover; at least one optical sheet and a reflective sheet, the light guide plate being between the optical sheet and the reflective sheet; first recesses (20a; 30a; 40a) disposed at the edges of the light guide plate, the reflective sheet and the at least one optical sheet; and first protrusions disposed on the bottom cover, the first protrusions being inserted into the first recesses (20a; 30a; 40a); wherein each of the first recesses (20a; 30a; 40a) is disposed on the edges of the light guide plate, the at least one optical sheet and the reflective sheet, wherein at least one connection hole (10f, 10g) is formed in the bottom cover, and wherein the connection hole allows the fixing members to be connected to the bottom cover through connection members, wherein: the second fixing member includes a first part configured to support a display panel, second parts protruded upwardly from the first part, the second parts configured to prevent movement of the display panel, third parts and fourth parts protruded downwardly from the first part, the third parts and fourth parts separated from each other and alternately disposed to be connected to inner and outer surfaces of a side wall of the bottom cover.