The source of information is one of the crucial elements when judging the credibility of the information. On the current Web, however, the information about the source is not readily available to the users. In this paper, we formulate the problem of identifying the information source as the problem of identifying the information sender configuration (ISC) of a Web page. An information sender of a Web page is an entity which is involved in the publication of the information on the page. An information sender configuration of a Web page describes the information senders of the page and the relationship among them. Information sender identification is a sub-problem of identifying ISC, and we present a method for extracting information senders from Web pages, along with its evaluation. ISC provides a basis for deeper analysis of information on the Web.