A sheet processing apparatus that forms a portion-to-be-processed on a sheet having pre-products , wherein the sheet is one of a plurality of sheets that are sent out one by one, the sheet processing apparatus comprising: at least one processing tool that takes a processable state in which the portion-to-be-processed is allowed to be formed and an unprocessable state in which the portion-to-be-processed is not allowed to be formed; and a control unit that controls an operation state of the at least one processing tool , wherein a margin is provided around each of the pre-products on the sheet , characterized in that the control unit is configured to control the at least one processing tool such that when the at least one processing tool moves from formation of a certain portion-to-be-processed in a certain pre-product on the sheet to formation of a next portion-to-be-processed of the same type as the certain portion-to-be-processed in a next pre-product on the sheet , a processable state holding process is executed to form a continuous portion-to-be-processed in which the certain portion-to-be-processed in the certain pre-product , a marginal portion-to-be-processed in the margin , and the next portion-to-be-processed in the next pre-product are formed continuously, by holding the processable state and forming the marginal portion-to-be-processed in the margin , and wherein when the at least one processing tool moves relatively with respect to the sheet so as to draw an inversed C-shaped or C-shaped trajectory in the conveyance perpendicular direction, the conveyance direction (F), and the conveyance perpendicular direction, the at least one processing tool is located outside the sheet . at least one processing tool that takes a processable state in which the portion-to-be-processed is allowed to be formed and an unprocessable state in which the portion-to-be-processed is not allowed to be formed; and a control unit that controls an operation state of the at least one processing tool , wherein a margin is provided around each of the pre-products on the sheet , characterized in that the control unit is configured to control the at least one processing tool such that when the at least one processing tool moves from formation of a certain portion-to-be-processed in a certain pre-product on the sheet to formation of a next portion-to-be-processed of the same type as the certain portion-to-be-processed in a next pre-product on the sheet , a processable state holding process is executed to form a continuous portion-to-be-processed in which the certain portion-to-be-processed in the certain pre-product , a marginal portion-to-be-processed in the margin , and the next portion-to-be-processed in the next pre-product are formed continuously, by holding the processable state and forming the marginal portion-to-be-processed in the margin , and wherein when the at least one processing tool moves relatively with respect to the sheet so as to draw an inversed C-shaped or C-shaped trajectory in the conveyance perpendicular direction, the conveyance direction (F), and the conveyance perpendicular direction, the at least one processing tool is located outside the sheet . <EOS>