An electronic (e-) commerce support system has a Web server to which each retailer makes an access via a terminal of each retailer over a network, thus performing access management for each retailer, a database storing data for each of functions required for e-commerce, and an application server to establish each of the functions by using the stored data, necessary functions among the functions required for e-commerce being offered to each retailer and available through the terminal of each retailer over the network.