A finishing panel using marble including a marble panel to be disposed at a front surface and a back body panel joined with a rear surface of the marble panel, wherein the back body panel comprises a supporting panel formed in the same size with the marble panel and attached to the marble panel, and a coupling panel positioned at a rear surface of the supporting panel and having both sides facing each other in complementary shape, and wherein one of the sides is formed with a groove part behind the supporting panel, and the other side is formed with a protrusion part, so that the groove part and the protrusion part of the coupling panel are engaged with a protrusion part and a groove part of adjacent coupling panels.