1. A method for managing JAVA applications executable in a user device, the method comprising steps of: (a) issuing a request for executing a second JAVA application, the request being issued by a first JAVA application and including a-execution type information, the execution type information containing information on a second application state of the second JAVA application, and a first application state of the first JAVA application while the second JAVA application is in the second application state; (b) changing the first JAVA application to the first application state specified in the execution type information while the second JAVA application is in the second application state; (c) executing the second JAVA application; and (d) killing the second JAVA application when a request for killing the second JAVA application is issued by the second JAVA application and re-changing the state of the first JAVA application changed in the step (b) according to the execution type information.