On the expressway, jet fans are essential for ventilating tunnels and are located in the places where they can operate most efficiently. Maintaining jet fans is difficult. Additionally should a fan fall, there is risk of a serious accident. In this report, in order to improve maintenance methods, prevent accidents and maintain maintenance efficiency, we propose a method of maintain ventilation facilities more safely and easily, as well as inspecting difficult area more efficiently. We considered five ways to improve maintenance. Firstly, install jet fans of JF1000 or under in the upper inspection area. Secondly, to allow easier inspection of metal emplacements and enough space for maintenance activities, install jet fans 1400mm from center line. Thirdly, secure sufficient working place. There should be a distance from the body of over 470mm, the head of over 330mm and the forearms of over 200mm from the tunnel lining and the jet fans to afford easy inspection of metal emplacements located above the outer line. Fourthly, place jet fans longitudinally to secure sufficient place for maintenance. Lastly, when jet fans of JF1000 are chosen to replace existing fans for ease of maintenance, the number of fans needs to be increased. We confirmed that we need to development of jet fans capable of producing wind speeds of over 37m/s to improve ventilation accuracy and reduce the number of fans.