A slitter device comprising: a let-off mechanism having a let-off driving unit on which a raw-cloth roller formed by winding up an elongated sheet material in a roll shape is mounted, and which has a let-off driving motor as a driving source for rotationally driving the raw-cloth roller; a cutter device for dividing the sheet material fed out from the let-off mechanism in a width direction of the sheet material to form a plurality of divided sheet materials (SM'), having a plurality of disk-shaped rotary blades provided according to the number of divisions of the sheet material, and having a support roll to which the rotary blade is pressed and around which the sheet material is wound; a take-up mechanism having a winding shaft (31a, 31b) on which a plurality of take-up reels for winding up each of the divided sheet materials (SM') are supported, and having a take-up driving unit which has a take-up driving motor as a driving source for rotationally driving the winding shaft (31a, 31b); a drive control device for controlling the driving of the let-off driving unit and the take-up driving unit, which performs the drive control of one of the let-off driving unit and the take-up driving unit as a tension control and performs the drive control of the other as a speed control; a roll driving motor that is connected to the support roll to rotationally drive the support roll; characterised by a first tension detecting unit for obtaining a raw-cloth tension value which is a tension value of the sheet material fed out from the let-off mechanism; and a second tension detecting unit for obtaining the divided material tension value which is the sum of the tension values of each of the divided sheet materials (SM'), wherein the drive control device includes a comparator to which the first tension detecting unit and the second tension detecting unit are connected, and which compares the raw-cloth tension value and the divided material tension value with each other, and a drive controller which controls an operating state of the roll driving motor such that the raw-cloth tension value and the divided material tension value coincide or substantially coincide with each other based on the comparison result of the comparator. a let-off mechanism having a let-off driving unit on which a raw-cloth roller formed by winding up an elongated sheet material in a roll shape is mounted, and which has a let-off driving motor as a driving source for rotationally driving the raw-cloth roller; a cutter device for dividing the sheet material fed out from the let-off mechanism in a width direction of the sheet material to form a plurality of divided sheet materials (SM'), having a plurality of disk-shaped rotary blades provided according to the number of divisions of the sheet material, and having a support roll to which the rotary blade is pressed and around which the sheet material is wound; a take-up mechanism having a winding shaft (31a, 31b) on which a plurality of take-up reels for winding up each of the divided sheet materials (SM') are supported, and having a take-up driving unit which has a take-up driving motor as a driving source for rotationally driving the winding shaft (31a, 31b); a drive control device for controlling the driving of the let-off driving unit and the take-up driving unit, which performs the drive control of one of the let-off driving unit and the take-up driving unit as a tension control and performs the drive control of the other as a speed control; a roll driving motor that is connected to the support roll to rotationally drive the support roll; characterised by a first tension detecting unit for obtaining a raw-cloth tension value which is a tension value of the sheet material fed out from the let-off mechanism; and a second tension detecting unit for obtaining the divided material tension value which is the sum of the tension values of each of the divided sheet materials (SM'), wherein the drive control device includes a comparator to which the first tension detecting unit and the second tension detecting unit are connected, and which compares the raw-cloth tension value and the divided material tension value with each other, and a drive controller which controls an operating state of the roll driving motor such that the raw-cloth tension value and the divided material tension value coincide or substantially coincide with each other based on the comparison result of the comparator.