Method and apparatus for distributing application programs in network

The peer belonging to a P2P network according to an embodiment of the invention (peer), the first file distribution to distribute in the form of an executable file needed to run the application unit; A second receiving unit for receiving file in the form of an executable file needed to run the application; And in that after the receiving the files required to execute the second application program, and a program execution environment setting unit that sets the environment in which to execute the file required to execute the second application. The file distribution unit, the first deploying a backup file for the file that may be changed during execution of the application, and deploying the same file as the source for the file does not change during execution of the first application.