1. An apparatus for tamper protection of an application code based on self modification, the apparatus comprising: an input unit that receives input codes to be used for an application; a code separator that separates the inputted codes into sensitive codes requiring application tamper protection and general codes including a sensitive method calling routine for calling the sensitive codes by analyzing the 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 a vector table generator for creating a vector table including vector information of the sensitive codes, to the sensitive codes, and inserts a sensitive method calling routine converter, which makes the sensitive method calling routine to 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, wherein, the sensitive code connector, the vector table generator, the sensitive method calling routine converter, and the sensitive codes are decoded, the vector table generator creates the vector table, and the sensitive method calling routine converter converts the sensitive method calling routine to call the sensitive codes, and when the sensitive method calling routine calls the sensitive codes through a vector value in the vector table, the sensitive code connector calls and executes a sensitive code corresponding to the vector value via the vector table and the address information of the sensitive codes.