Abstract: An illumination device includes an illumination lamp installed to a device housing, a sensor for use in controlling the lighting operation of the illumination lamp, and a sensor attachment unit through which the sensor is detachably attached to the device housing such that a sensing unit of the sensor is exposed to the outside. The illumination device further includes a decoration member for attachment to the sensor attachment unit when the sensor is not attached to the sensor attachment unit, the decoration member having substantially the same outward appearance as that of the sensor. The sensor and the decoration member are interchangeably attached to the sensor attachment unit.

Abstract: An illumination control system includes lighting apparatuses connected to a communications line and a number of functional units of plural kinds functioning to detect information from ambient environments of the lighting apparatuses. Each lighting apparatus includes a lamp, an illumination circuit, a communication unit, a control unit, and a unit attaching part to which the functional unit is detachably attached. Each lighting apparatus belongs to one or more of plural groups corresponding to the functional units, the groups being operated based on information detected by the respective functional units. A functional unit having a detecting function corresponding to an operation of each group is attached to each unit attaching part of at least one lighting apparatus of each group, and each communication unit of the at least one lighting apparatus sends the control signal including information detected by the corresponding functional unit to another lighting apparatus in the same group.