may comprise natural stone or artificial stone without being limited to a specific material according to the present invention it is preferable that the surface material layer comprises natural stone natural stone provides an antique and graceful effect particularly natural stone transmits light to provide an indirect lighting effect to be specific an example of natural stone may be marble granite stone limestone or sandstone but is not limited thereto according to the present invention an area of the surface material layer is appropriately selected to conform to a size of the floor to which the composite panel is to be applied for example may range from 1000 cm 2 to 8000 cm 2 further a length and a width of the surface material layer may be adjusted to be within a range of 400 mm to 800 mm further in the present invention a thickness of the surface material layer is not limited to a specific value for example it may range from 2 mm to 5 mm if the thickness of the surface material layer is less than 2 mm strength is reduced so that the surface material layer may be damaged on the other hand if the thickness is more than 5 mm a manufacturing cost may be increased in the present invention the substrate layer is formed under the surface material.