1. A method for operating multiple standby states, performed by a Set Top Box (STB) comprising processors which control the STB by using a framework, the method comprising: releasing, by the framework, a full wake lock for the STB, the full wake lock is for sustaining a power state in which both main functions and background functions of the STB are able to be performed; acquiring, by the framework, a partial wake lock for the STB and entering a first standby state, wherein the partial wake lock is for sustaining a power state in which only background functions of the STB are able to be performed; shutting down a main processor of the STB; releasing, by the framework, the partial wake lock and entering a second standby state; waking up the main processor of the STB; and acquiring, by the framework, the partial wake lock and returning to the first standby state.