A lighting device comprising: a housing comprising a bottom opening; a substrate comprising a top surface; a plurality of light emitting devices disposed on the top surface of the substrate; a support comprising a sloped surface forming an obtuse angle (a) with the top surface of the substrate; an optical plate disposed on the plurality of light emitting devices and the support; a reflecting sheet disposed on the sloped surface of the support, wherein: the reflecting sheet comprises a base sheet having a circular shape and a circular opening disposed at a center of the base sheet, the base sheet comprises both ends spaced from each other, the reflecting sheet comprises a connecting sheet extending from one end of the both ends toward an other end of the both ends, the base sheet has at least one incision disposed at the other end, the housing has a plurality of projections each extending outwardly from an outer surface of the housing, the projections have the function of fixing the lighting device to a particular point, wherein the lighting device further comprises a base, the housing is disposed on the base and coupled to the base, the support comprises a guide and a reflecting portion, the guide projects upward from an upper portion of the reflecting portion and limits the movement of the optical plate by guiding the outer circumference of the optical plate, the optical plate, the support, the reflecting sheet, the substrate and the light emitting devices are received in the housing, the housing comprises an upper part and a lower part, an outer diameter of the upper part is greater than an outer diameter of the lower part. a housing comprising a bottom opening; a substrate comprising a top surface; a plurality of light emitting devices disposed on the top surface of the substrate; a support comprising a sloped surface forming an obtuse angle (a) with the top surface of the substrate; an optical plate disposed on the plurality of light emitting devices and the support; a reflecting sheet disposed on the sloped surface of the support, wherein: the reflecting sheet comprises a base sheet having a circular shape and a circular opening disposed at a center of the base sheet, the base sheet comprises both ends spaced from each other, the reflecting sheet comprises a connecting sheet extending from one end of the both ends toward an other end of the both ends, the base sheet has at least one incision disposed at the other end, the housing has a plurality of projections each extending outwardly from an outer surface of the housing, the projections have the function of fixing the lighting device to a particular point, wherein the lighting device further comprises a base, the housing is disposed on the base and coupled to the base, the support comprises a guide and a reflecting portion, the guide projects upward from an upper portion of the reflecting portion and limits the movement of the optical plate by guiding the outer circumference of the optical plate, the optical plate, the support, the reflecting sheet, the substrate and the light emitting devices are received in the housing, the housing comprises an upper part and a lower part, an outer diameter of the upper part is greater than an outer diameter of the lower part. the reflecting sheet comprises a base sheet having a circular shape and a circular opening disposed at a center of the base sheet, the base sheet comprises both ends spaced from each other, the reflecting sheet comprises a connecting sheet extending from one end of the both ends toward an other end of the both ends, the base sheet has at least one incision disposed at the other end, the housing has a plurality of projections each extending outwardly from an outer surface of the housing, the projections have the function of fixing the lighting device to a particular point, wherein the lighting device further comprises a base, the housing is disposed on the base and coupled to the base, the support comprises a guide and a reflecting portion, the guide projects upward from an upper portion of the reflecting portion and limits the movement of the optical plate by guiding the outer circumference of the optical plate, the optical plate, the support, the reflecting sheet, the substrate and the light emitting devices are received in the housing, the housing comprises an upper part and a lower part, an outer diameter of the upper part is greater than an outer diameter of the lower part.