A lighting apparatus comprising: an LED unit formed in an elongated shape, said LED unit being provided with a plurality of lighting units on one surface in the thickness direction thereof, each of said lighting units having a LED chip; a main body; a reflective plate made of metal and configured to control the light from said LED unit to be an intended distribution, said reflective plate being held by said main body; a lighting device configured to light said LED unit, said lighting device being replaceably attached to said main body; and a heat radiation block to which said LED unit is replaceably attached and, wherein the heat radiation block is configured to dissipate the heat generated in said LED unit, and wherein said heat radiation block is arranged at the other surface side in the thickness direction of said LED unit, wherein said reflective plate has an installation portion for installing said LED unit, wherein said heat radiation block is held by said reflective plate, and wherein said LED unit has a flat portion at its light extracting surface from said lighting unit, characterized in that said flat portion is in the same plane with a surrounding area of said installation portion in a reflective surface of said reflective plate; in that said reflective plate has an adjusting piece extending from said reflective plate toward said heat radiation block into the thickness direction of said LED unit, and in that said adjusting piece has a first height in the thickness direction of said LED unit, thereby the height of said reflective plate is determined by said adjusting piece, and in that said first height of said adjusting piece is set so that said flat portion at the light extracting surface from said lighting unit in said LED unit is in the same plane with said surrounding area of said installation portion in said reflective surface of said reflective plate. an LED unit formed in an elongated shape, said LED unit being provided with a plurality of lighting units on one surface in the thickness direction thereof, each of said lighting units having a LED chip; a main body; a reflective plate made of metal and configured to control the light from said LED unit to be an intended distribution, said reflective plate being held by said main body; a lighting device configured to light said LED unit, said lighting device being replaceably attached to said main body; and a heat radiation block to which said LED unit is replaceably attached and, wherein the heat radiation block is configured to dissipate the heat generated in said LED unit, and wherein said heat radiation block is arranged at the other surface side in the thickness direction of said LED unit, wherein said reflective plate has an installation portion for installing said LED unit, wherein said heat radiation block is held by said reflective plate, and wherein said LED unit has a flat portion at its light extracting surface from said lighting unit, characterized in that said flat portion is in the same plane with a surrounding area of said installation portion in a reflective surface of said reflective plate; in that said reflective plate has an adjusting piece extending from said reflective plate toward said heat radiation block into the thickness direction of said LED unit, and in that said adjusting piece has a first height in the thickness direction of said LED unit, thereby the height of said reflective plate is determined by said adjusting piece, and in that said first height of said adjusting piece is set so that said flat portion at the light extracting surface from said lighting unit in said LED unit is in the same plane with said surrounding area of said installation portion in said reflective surface of said reflective plate.