Abstract: A printing press operating method and a printing press capable of quickly stabilizing the tension of webs and improving cost effectiveness by reducing the amount of wasted paper are provided. An operating method of a printing press that is provided with a plurality of rollers on a web path, that conveys the web with these rollers, and that prints on the web with printing cylinders includes carrying out a tension-application operation for increasing the tension of the web while at least one of the rollers affecting the tension on the web, among the rollers provided on the web path, is set to an attached state with respect to the web and printing cylinders are set to a detached state, and then after this operation, accelerating the web to a printable state. In this way the tension of the web quickly stabilizes, and the amount of wasted paper can be reduced.