A method for manufacturing toilet roll products applied with chemicals: comprising: continuously manufacturing a secondary paper roll for the toilet roll products, by using purposely a ply machine, from a primary paper roll, which has been manufactured and wound by a paper manufacturing machine, wherein the ply machine includes a multi-ply forming unit, which performs multi-ply forming on single-sheets from the primary paper rolls, reeled out of a plurality of the primary paper rolls along the continuation direction so as to form a multi-ply continuous sheet, a chemicals applying unit, which is provided at a post stage of the multi-ply forming unit so as to apply the chemicals to the multi-ply continuous sheet, and a winding unit, which winds the multi-ply continuous sheet applied with the chemicals so as to form the secondary paper roll having a width plural times or more a width of a toilet roll; setting the secondary paper roll for the toilet paper products, which has been manufactured by the ply machine and applied with the chemicals in the ply machine, in a paper roll support portion of a winder; reeling out a multi-ply-sheet from the secondary paper roll, which has been applied with the chemicals, in the winder; forming perforation lines on the multi-ply-sheet from the secondary paper roll in the width direction of the multi-ply-sheet from the secondary paper roll at a predetermined interval in the flow direction; and after that, rewinding the multi-ply-sheet from the secondary paper roll, which has been provided with the perforation lines with a winding diameter of a toilet roll, so as to manufacture a log for the toilet roll; conveying the log manufactured in the winder to a log cutter; cutting the log into the width of the toilet roll by the log cutter so as to become individual toilet rolls; and putting one or plural toilet rolls in a product packing bag in a packing facility so as to obtain the toilet roll products. continuously manufacturing a secondary paper roll for the toilet roll products, by using purposely a ply machine, from a primary paper roll, which has been manufactured and wound by a paper manufacturing machine, wherein the ply machine includes a multi-ply forming unit, which performs multi-ply forming on single-sheets from the primary paper rolls, reeled out of a plurality of the primary paper rolls along the continuation direction so as to form a multi-ply continuous sheet, a chemicals applying unit, which is provided at a post stage of the multi-ply forming unit so as to apply the chemicals to the multi-ply continuous sheet, and a winding unit, which winds the multi-ply continuous sheet applied with the chemicals so as to form the secondary paper roll having a width plural times or more a width of a toilet roll; a multi-ply forming unit, which performs multi-ply forming on single-sheets from the primary paper rolls, reeled out of a plurality of the primary paper rolls along the continuation direction so as to form a multi-ply continuous sheet, a chemicals applying unit, which is provided at a post stage of the multi-ply forming unit so as to apply the chemicals to the multi-ply continuous sheet, and a winding unit, which winds the multi-ply continuous sheet applied with the chemicals so as to form the secondary paper roll having a width plural times or more a width of a toilet roll; setting the secondary paper roll for the toilet paper products, which has been manufactured by the ply machine and applied with the chemicals in the ply machine, in a paper roll support portion of a winder; reeling out a multi-ply-sheet from the secondary paper roll, which has been applied with the chemicals, in the winder; forming perforation lines on the multi-ply-sheet from the secondary paper roll in the width direction of the multi-ply-sheet from the secondary paper roll at a predetermined interval in the flow direction; and after that, rewinding the multi-ply-sheet from the secondary paper roll, which has been provided with the perforation lines with a winding diameter of a toilet roll, so as to manufacture a log for the toilet roll; conveying the log manufactured in the winder to a log cutter; cutting the log into the width of the toilet roll by the log cutter so as to become individual toilet rolls; and putting one or plural toilet rolls in a product packing bag in a packing facility so as to obtain the toilet roll products.