The present invention provides a vehicle room light apparatus which is small in size and achieves high heat dissipation. The vehicle room light apparatus includes a light source; a switch; and a case including a front surface as a designed surface and a back surface. The back surface having a first region on which the light source and the switch are arranged in line, a second region which has a space extending along the first region and an opening continuing to the space, a partition wall which separates the first and the second regions.