Provided is a liquid crystal backlight device 3 for emitting light onto a liquid crystal panel, the liquid crystal backlight device being provided with: interconnecting boards 7a, 7b electrically connecting light emitting element boards 6 equipped with a plurality of light emitting elements 5 to control boards for controlling the light emission of the plurality of light emitting elements; a mounting member 9 having a mounting surface on which the light emitting element boards and the interconnecting boards are mounted; first connectors 8 mounted to the light emitting element boards; second connectors 2 mounted to the interconnecting boards; and a supported part that is supported when the first connectors and the second connectors are pushed against the mounting surface. The first connectors and the second connectors have positional misalignment tolerating means for tolerating positional misalignment between the light emitting element boards and the interconnecting boards within a surface intersecting the mounting surface and within a surface along the mounting surface. The first connectors and the second connectors are fitted from a direction perpendicular to the mounting surface when mounting the light emitting element boards or the interconnecting boards to the mounting member.