An Electronic Program Guide (EPG) storing method, the EPG storing method including: receiving an EPG including program information for at least one program; and storing the program information included in the EPG in a database assigned to an index number corresponding to the at least one program with reference to an index map in which index numbers are respectively assigned to programs. Accordingly, users can easily obtain the previous information for the user's desired program from a device that the user watches without using other devices, such as the Internet.