Abstract: A printing apparatus is formed of a printing drum which is rotationally driven around a central axis of itself with a heatsensitive stencil sheet around an outer circumferential surface of itself, liquid ejecting device for forming an image from photothermal conversion material on the stencil sheet by ejecting a liquid containing the photothermal conversion material to the stencil sheet and for forming an image on a printing paper by ejecting a liquid containing a colorant and the photothermal conversion material, light radiating device for perforating the stencil sheet by radiating light to the stencil sheet with the photothermal conversion material on it, a pressing device for pressing the printing paper against the printing drum, the printing paper being supplied in synchronization with rotation of the printing drum, and for transferring an ink supplied to an inner spherical surface of the printing drum to the printing paper through the perforated stencil sheet, and control device for controlling diameters