A display apparatus includes a demultiplexing unit which extracts program clock reference (PCR) information for synchronizing image information and voice information of a received image signal; a syntax analyzing unit which identifies a first and a second packet identification number of a packet having the PCR information so that the demultiplexing unit can extract the PCR information; and a controlling unit which, if the first packet identification number and the second packet identification number are different therebetween, controls the syntax analyzing unit to set one of the first packet identification number and the second packet identification number that corresponds to the packet having the PCR information, in the demultiplexing unit.