A lighting-up device includes: a power supply circuit which supplies power to a light source; a wireless communication circuit including an antenna; and a metallic casing which includes metal, and houses the power supply circuit and the wireless communication circuit. The metallic casing has a first side face and a second side face which share a side, the first side face is provided with a first slit which extends in a first direction intersecting with the side, from a first portion of the side other than both ends of the side, the second side face is provided with a second slit which extends in a second direction intersecting with the side, from a second portion of the side other than the both ends of the side, and each of the first slit and the second slit is electromagnetically coupled to the antenna and functions as a slot antenna.