A log roll manufacturing apparatus comprising: a yet-to-be-wound base-paper delivery unit that delivers multiple-layer base paper as yet-to-be-wound base paper, the multiple-layer base paper being fed from a plurality of parent rolls (10A, 10B) and being constituted of stacked sheets of base paper fed from the plurality of parent rolls (10A, 10B); and a processing-winding unit that performs a predetermined process on the yet-to-be-wound base paper delivered from the yet-to-be-wound base-paper delivery unit and that winds up the yet-to-be-wound base paper by a predetermined length so as to form a one-ply or multi-ply log roll, wherein the processing-winding unit includes one or more sub processing-winding units in addition to a main processing-winding unit to be preferentially used during a log roll manufacturing process, wherein a base-paper separating unit and a base-paper guide unit are provided between the yet-to-be-wound base-paper delivery unit and the processing-winding unit, the base-paper separating unit separating the yet-to-be-wound base paper constituted of multiple layers of base paper (11a, 11b) into sheets (12a, 12b) of single-layer and/or multiple-layer separated yet-to-be-wound base paper, the base-paper guide unit guiding the sheets (12a, 12b) of single-layer or multiple-layer separated yet-to-be-wound base paper separated at the base-paper separating unit separately toward the main processing-winding unit and the one or more sub processing-winding units, wherein the number of parent rolls (10A, 10B) that can be handled by the yet-to-be-wound base-paper delivery unit is larger than the number of processing-winding units installed, and wherein multiple-layer yet-to-be-wound base paper constituted of stacked sheets (12a, 12b) of base paper fed from all of the parent rolls (10A, 10B) is separated by the base-paper separating unit such as to include multiple-layer separated yet-to-be-wound base paper, wherein at least the multiple-layer separated yet-to-be-wound base paper is guided to the main processing-winding unit by the base-paper guide unit, and wherein remaining separated yet-to-be-wound base paper separated into a single-layer and/or multiple layers is guided to any of the sub processing-winding units, so that the log roll manufacturing apparatus simultaneously manufactures a multi-ply log roll at the main processing-winding unit and a one-ply log roll and/or a multi-ply log roll at the remaining sub processing-winding unit. a yet-to-be-wound base-paper delivery unit that delivers multiple-layer base paper as yet-to-be-wound base paper, the multiple-layer base paper being fed from a plurality of parent rolls (10A, 10B) and being constituted of stacked sheets of base paper fed from the plurality of parent rolls (10A, 10B); and a processing-winding unit that performs a predetermined process on the yet-to-be-wound base paper delivered from the yet-to-be-wound base-paper delivery unit and that winds up the yet-to-be-wound base paper by a predetermined length so as to form a one-ply or multi-ply log roll, wherein the processing-winding unit includes one or more sub processing-winding units in addition to a main processing-winding unit to be preferentially used during a log roll manufacturing process, wherein a base-paper separating unit and a base-paper guide unit are provided between the yet-to-be-wound base-paper delivery unit and the processing-winding unit, the base-paper separating unit separating the yet-to-be-wound base paper constituted of multiple layers of base paper (11a, 11b) into sheets (12a, 12b) of single-layer and/or multiple-layer separated yet-to-be-wound base paper, the base-paper guide unit guiding the sheets (12a, 12b) of single-layer or multiple-layer separated yet-to-be-wound base paper separated at the base-paper separating unit separately toward the main processing-winding unit and the one or more sub processing-winding units, wherein the number of parent rolls (10A, 10B) that can be handled by the yet-to-be-wound base-paper delivery unit is larger than the number of processing-winding units installed, and wherein multiple-layer yet-to-be-wound base paper constituted of stacked sheets (12a, 12b) of base paper fed from all of the parent rolls (10A, 10B) is separated by the base-paper separating unit such as to include multiple-layer separated yet-to-be-wound base paper, wherein at least the multiple-layer separated yet-to-be-wound base paper is guided to the main processing-winding unit by the base-paper guide unit, and wherein remaining separated yet-to-be-wound base paper separated into a single-layer and/or multiple layers is guided to any of the sub processing-winding units, so that the log roll manufacturing apparatus simultaneously manufactures a multi-ply log roll at the main processing-winding unit and a one-ply log roll and/or a multi-ply log roll at the remaining sub processing-winding unit.