The present invention permits users to obtain detailed information concerning those portions of web contents in which they are most interested and provides an information extraction system. In an embodiment, the information extraction system comprises a server and a client, connected via a communication network, wherein the server provides a data file for a client to browse; and wherein the client includes a browser for displaying the contents of the data file that is received from the server via the communication network, an operation event detection analyzer for detecting a predetermined specific operation based on a user's operation when the user reads the contents of the data file displayed by the browser, and a text extractor for extracting information that is displayed at a location whereat the specific operation that is detected by the operation event analyzer is performed on a display screen of the browser.