The city formation around a new campus of Kyushu University is in progress according to campus relocation of the university. In the Organization for Promotion Academic City by Kyushu University (OPACK), which is an organization for promoting the city formation of the new campus and surrounding area, the author is cooperating to promote the city formation by industry-academia cooperation as a university professor. This research considers the relationship between the industry-university cooperation and the contribution to society by university from the point of view of mechanical engineering in accordance with the experience and information obtained by the author's activities in this organization, and tries to find the ideal way of the industry-university cooperation. This is the third report that introduce activities of Itoshima City, which has been performed cooperating with Kyushu University, since the City established in 2010. At first the outline of Itoshima City is described, it is told that a trigger of collaboration activities with Kyushu University was campus relocation to this city. Two main projects have been performed since 2010; the former is to support a research on the subject related to the present problems of Itoshima City, the latter is to support the events stimulating friendship between the citizen and the university staff and students. Both projects became successful. After describing a problem that maintenance of such a good relationship will not continue after the campus moving completes, it is stated that it will be resolved with a reason.