The present invention relates to a portable computer comprising a main body unit which forms an image signal by reading and processing data; and a display unit which is plurally provided and has a plate surface displaying an image thereon and overlapping each other to rotate with respect to the main body casing, is detachably mounted in the display supporter, displays an image only on a most front plate surface when mounted in the display supporter, receives an image signal of the most front plate surface and selectively displays a same or different images thereon if it is separated from the display supporter.Accordingly, applicability and convenience of the portable computer may improve.