Apparatus and method for displaying a watermark on screen

PURPOSE: A device for displaying a watermark on a screen and a method thereof are provided to display a watermark on the screen, thereby enabling a user to recognize significance of contents. CONSTITUTION: When an application is executed, or a document is opened by an operation of a user, a monitoring unit(110) monitors a message generated in an operation system. A watermark display determination unit(130) determines whether or not a watermark is displayed based on the message and a screen watermark display policy. When the watermark is displayed, a watermark display unit(150) displays the watermark on the screen. [Reference numerals] (110) Monitoring unit; (130) Watermark display determination unit; (150) Watermark display unit; (200) Communication network; (300) Manager terminal;