To provide an electric apparatus, a power supply, and a lighting device which are suitable for air cooling and enabled to be downsized.

By arranging on a base 11 a plurality of groups of an electric element 12 and connecting wire terminals 16, 17, 18 lined up in series in such a manner that each group is placed zigzag, a plurality of groups of the electric elements and terminals (12, 16, 17, 18), (12a, 16a, 17a, 18a), (12b, 16b, 17b, 18b), and so on are enabled to be placed efficiently and densely. In addition, because it forms cooling paths on the base 11, cooling air can efficiently be circulated from a fan 13 mounted at the edge of the base 11.