Power supply for illumination and luminaire

A luminaire includes a light-emitting module (2), a first lighting circuit (7) and a back-flow preventing circuit (8). The light-emitting module (2) includes a light-emitting element (4) and a capacitive element (5). The first lighting circuit (7) is supplied with power from the first power supply (6) and lights the light-emitting element (4). The back-flow preventing circuit (8) interrupts current flowing in a direction from the capacitive element (5) to the first lighting circuit (7).