Disclosed is a technology associated with booting up a mobile communication terminal equipped with a user identification module (UIM).A method of improving the boot speed of a mobile communication terminal equipped with a UIM according to the present invention includes: a) handing over controllership, by a user interface (UI) task responsible for an initial UI process, to a UIM task in a process of reading a phonebook stored in the UIM during booting; b) setting parameters necessary for reading the phonebook stored in the UIM by the UIM task which has taken over the controllership from the UI task; c) reading records composing the phonebook one by one and copying each record into RAM by the UIM task after setting of the parameters is completed; and d) handing over the controllership to the UI task by the UIM task after the UIM task copies the records into the RAM.
