Abstract: Provided are an online networking system for an efficient operation of restaurants and a method therefore, in which restaurant customers and food material providers input order sheets and estimations of food material prices into a website and restaurants receive the order sheets and the estimations via facsimile so that restaurants serve more customers in circumstances of limited equipment, staffs, place, and time, and purchase food materials from the food material providers presenting a lowest price. The online networking system includes a service provider for operating and managing a web server that provides the website, restaurant customers, food material providers, and the restaurant connected to the web server via Internet terminals and a facsimile.