1. A printing method comprising: printing a plurality of images on a continuous sheet and forming a mark in a non-image area between adjacent two images; and cutting the sheet on a basis of a detection of the mark, wherein a length of the non-image area is set on a basis of image data in a rear end part of a precedent image of the two images, and a position where a mark detecting operation in the non-image area is started, is determined on a basis of the length of the non-image area.