According to one embodiment, a light-emitting module includes a substrate and a light-emitting element mounted on the substrate. One side of the light-emitting module has a length of 160 mm to 200 mm. An optical output per area for a square section of the light-emitting module having a side length equal to the length of the one side is 700 lm to 1300 lm, and a rated power consumption of the square section is equal to or less than 16 W. A plurality of such light-emitting modules are arranged and combined to form various luminaires having shapes and lighting performances equivalent to a shape and lighting performance of a luminaire including a fluorescent lamp as a light source.