To provide a luminaire with a built-in human body detecting sensor and an excellent appearance design, easy for wiring work and mounting work of the luminaire itself.

This luminaire 1 with the built-in human body detecting sensor is composed of a base board 5 to be attached with a light source 4 such as a lamp, a human body detecting microwave sensor 9 installed in the base board 5, and a control circuit 12 to control switching on and off of the light source such as the lamp by a signal from the microwave sensor 9. Since the microwave sensor 9 is hidden inside the base board 5 so as not to be exposed outside, the external appearance of the luminaire looks fine. In addition, an opening for a sensor conventionally provided is not required, it can be freely designed in terms of an appearance design. Furthermore, a power source for detecting the human body can be obtained from an lighting circuit, and wiring work can be simply and speedily carried out.