User terminal device and contents streaming method using the same

Disclosed are a user terminal device and a content transmitting method using the same. The content transmitting method includes a first transmission step in which a part of content is converted into a first format and transmitted to an outer device based on information for displaying the content in an outer device at an initial stage and a second transmission step in which the content is transmitted to the outer device by being converted into a second format which is different from the first format after the part converted into the first format is transmitted to the outer device. [Reference numerals] (110) Communication unit; (120) Input unit; (130) Storage unit; (140) Control unit