To suppress deficient boring or variation in bored hole diameters in a stencil base paper plate making apparatus for making stencil base paper with a plate making width wider than an ordinary plate making width.

Either of an ordinary plate making mode of plate making with a predetermined width of the plate making width in the main scanning direction Y of a stencil base paper M and a wider plate making mode of plate making with a width wider than the predetermined width of the plate making width in the main scanning direction Y of the stencil base paper is selectively set. A thermal head 2 is controlled so that heat generating energy of a heat generating element in the wider plate making mode is larger than the heat generating energy of the heat generating element in the ordinary plate making mode.