A planographic printing plate supply unit comprising: carrying rollers rotating while pressing a stacking bundle, in which planographic printing plates and covering papers are stacked alternately, so as to carry the planographic printing plate and covering paper at the top of the stacking bundle, wherein convex portions which are elastically deformed when pressing the stacking bundle and whose contact area with the planographic printing plate is larger after being elastically deformed than before are provided on the outside periphery of the carrying roller.