Abstract: To create a media plan in which various advertisement publications including the distribution of an advertising banner is optimized When accepting a manuscript created through an advertising agency (14) or a REP (16) and including information indicative of a period, a budget and a target user, a media plan creating server (18) acquires data including an access log of internet of a sample user in a sample family from an internet audience behavior research institution (20). Next, the media plan creating server (18) selects a predetermined number of prospective sites presumed to have an advertising effect based on the access log of the user which is coincident with conditions of the target user, and calculates an index to find a combination thereof in relation to the prospective sites. A media plan in which an advertisement period and a budget are allocated to each of the combinations is transmitted to the advertising agency (14) or the REP (16).