A lighting apparatus comprising: a light-emission unit having plate shape; and a base unit configured to be detachably attached thereto the light-emission unit, the base unit having substantially rectangular shape, wherein the base unit comprises: a power supply rail for supplying electricity to the light-emission unit, the power supply rail having rail-shape and extending in a longitudinal direction of the base unit; and a support section supporting the light-emission unit, wherein the light-emission unit comprises: a luminescent panel; a control circuit configured to control lighting of the luminescent panel; and an electrically conductive connection terminal (17; 117) electrically connecting the control circuit to the power supply rail, wherein the base unit is formed so as to be capable of being attached thereto a plurality of the light-emission units along the longitudinal direction of the base unit, and wherein the connection terminal (17; 117) is connected to an arbitrary point of the rail-shaped power supply rail, the lighting apparatus being characterised in that: the base unit has substantially rectangular shape so as to have a first long side and a second long side along the longitudinal direction thereof, the support section comprises a holding element and an engaging element, wherein the holding element is provided at a side of the first long side continuously or discontinuously, and the engaging element is provided at a side of the second long side continuously or discontinuously, and the light-emission unit comprises a held element held by the holding element and an engaged element engaged with the engaging element, and wherein the engaged element includes a movable protrusion and a spring, and the movable protrusion is elastically biased by the spring in a direction substantially perpendicular to the longitudinal direction of the base unit at the side of the second long side, so that the engaged element is engaged with the engaging element. a light-emission unit having plate shape; and a base unit configured to be detachably attached thereto the light-emission unit, the base unit having substantially rectangular shape, wherein the base unit comprises: a power supply rail for supplying electricity to the light-emission unit, the power supply rail having rail-shape and extending in a longitudinal direction of the base unit; and a support section supporting the light-emission unit, a power supply rail for supplying electricity to the light-emission unit, the power supply rail having rail-shape and extending in a longitudinal direction of the base unit; and a support section supporting the light-emission unit, wherein the light-emission unit comprises: a luminescent panel; a control circuit configured to control lighting of the luminescent panel; and an electrically conductive connection terminal (17; 117) electrically connecting the control circuit to the power supply rail, a luminescent panel; a control circuit configured to control lighting of the luminescent panel; and an electrically conductive connection terminal (17; 117) electrically connecting the control circuit to the power supply rail, wherein the base unit is formed so as to be capable of being attached thereto a plurality of the light-emission units along the longitudinal direction of the base unit, and wherein the connection terminal (17; 117) is connected to an arbitrary point of the rail-shaped power supply rail, the lighting apparatus being characterised in that: the base unit has substantially rectangular shape so as to have a first long side and a second long side along the longitudinal direction thereof, the base unit has substantially rectangular shape so as to have a first long side and a second long side along the longitudinal direction thereof, the support section comprises a holding element and an engaging element, wherein the holding element is provided at a side of the first long side continuously or discontinuously, and the engaging element is provided at a side of the second long side continuously or discontinuously, and the light-emission unit comprises a held element held by the holding element and an engaged element engaged with the engaging element, and wherein the engaged element includes a movable protrusion and a spring, and the movable protrusion is elastically biased by the spring in a direction substantially perpendicular to the longitudinal direction of the base unit at the side of the second long side, so that the engaged element is engaged with the engaging element.