A display apparatus, and more particularly, a display apparatus capable of indicating a picture-in-picture (PIP) function on a color display tube (CDT) monitor, is provided. The display apparatus includes a signal dispensing unit for dispensing an output signal output from a personal computer (PC) in the form of an analog or digital signal and outputting the same, a signal processing unit for performing PIP signal processing enabling one of a digital PC signal generated by the signal dispensing unit and a decoded TV/video signal input from an outside source to be displayed on a main screen and the other to be displayed on one or more sub-screens, and for processing the TV/video signal to be displayed alone on the main screen, an outputting unit for outputting an analog PC signal generated from the signal dispensing unit in response to a control signal for displaying only the PC signal, and outputting an output signal of the signal processing unit in response to a control signal for displaying the PIP and TV/video signals, and a monitor for amplifying the signal output from the outputting unit to be displayed. According to the display apparatus, the PIP function can be realized, and also, a signal of high definition can be displayed on the CDT monitor.