1. An apparatus for tamper protection of an application code based on self modification, the apparatus comprising: an input unit that receives codes to be used for an application; a code separator that separates the inputted code into sensitive codes requiring application tamper protection and general codes including sensitive method calling routine for calling the sensitive codes by analyzing input codes; an encoder that encrypts the sensitive codes and inserts the address of a sensitive code connector storing the address information of the sensitive codes; a controller that converts the sensitive method calling routine to be able to call dummy codes by inserting the dummy codes to the general codes, inserts vector table generator for creating a vector table including vector information of the sensitive codes, to the sensitive codes, and insert a sensitive method calling routine converter, which makes the sensitive method calling routine call the sensitive codes when the application is executed, to the sensitive codes; and a code combiner that creates the application by combining the general codes and the sensitive codes.