To provide an indoor illuminating device capable of being mounted with a high degree of freedom.

An indoor illuminating device 11 includes: a housing 12; a light source that is accommodated in the housing 12 from an opening 21 formed in the housing 12; electric wires 31 that are led into the housing 12 from the opening part 21 of the housing 12 and supplies electric power to the light source; and a cover 15 that covers the opening 21 of the housing 12. A plurality of through-holes 50 through which the electric wires 31 can be drawn out to the same direction at different positions are formed between the housing 12 and the cover 15 by installing the cover 15 to the housing 12.