A service providing system passes an instruction form representing an instruction for each server from one server to another to make the server execute its target instruction in the instruction form while protecting confidentiality of the instruction for each server in the instruction form. By combining page dividing (of outputting a file of a predetermined page extracted from a document file having a plurality of pages) provided by a server with e-mail transmission provided by another server, the system implements a cooperative service of extracting a top page from a file of a document entered into an instruction input unit by a user and sending the top page via e-mail to a predetermined destination. The instruction input unit separately encrypts each description about process details for the servers using a public key for the corresponding server, creates instruction forms containing the encrypted descriptions, and sends the instruction forms to the server providing the page dividing service.