A cutting device for cutting a cutting object included in a structure, the cutting device comprising: a grasp unit including a first grasper and a second grasper that are movable in an opening and closing directions, in which direction the first grasper and the second grasper come close to each other or go away from each other, to grasp the cutting object therebetween in the opening and closing directions; a drive mechanism that moves the first grasper and the second grasper relatively to each other in the opening and closing directions; a cutting unit disposed side by side with the first grasper and the second grasper and configured to cut the cutting object with a movement of the cutting unit in a cutting direction along with the opening and closing directions; a main unit supporting the first and second graspers (50a, 50b) movably in the opening and closing directions and supporting the cutting unit movably in the cutting direction; a feed mechanism that moves the cutting unit in the opening and closing directions; and a position setting means that sets a cutting start position and a cutting end position based on respective positions of the first grasper and the second grasper that are grasping the cutting object, respectively, the cutting start position being a position at which an operation of the cutting unit and the movement of the cutting unit for cutting the cutting object are started, the cutting end position being a position at which the operation of the cutting unit and the movement of the cutting unit for cutting the cutting object are ended; characterized in that the position setting means includes a detector (70a, 70b) that detects positional information of at least one of the first grasper and the second grasper that are grasping the cutting object, the position setting means being configured to set the cutting start position and the cutting end position based on the positional information detected by the detector (70a, 70b). a grasp unit including a first grasper and a second grasper that are movable in an opening and closing directions, in which direction the first grasper and the second grasper come close to each other or go away from each other, to grasp the cutting object therebetween in the opening and closing directions; a drive mechanism that moves the first grasper and the second grasper relatively to each other in the opening and closing directions; a cutting unit disposed side by side with the first grasper and the second grasper and configured to cut the cutting object with a movement of the cutting unit in a cutting direction along with the opening and closing directions; a main unit supporting the first and second graspers (50a, 50b) movably in the opening and closing directions and supporting the cutting unit movably in the cutting direction; a feed mechanism that moves the cutting unit in the opening and closing directions; and a position setting means that sets a cutting start position and a cutting end position based on respective positions of the first grasper and the second grasper that are grasping the cutting object, respectively, the cutting start position being a position at which an operation of the cutting unit and the movement of the cutting unit for cutting the cutting object are started, the cutting end position being a position at which the operation of the cutting unit and the movement of the cutting unit for cutting the cutting object are ended; characterized in that the position setting means includes a detector (70a, 70b) that detects positional information of at least one of the first grasper and the second grasper that are grasping the cutting object, the position setting means being configured to set the cutting start position and the cutting end position based on the positional information detected by the detector (70a, 70b).