A tool change method of storing, in a tool storage unit, a plurality of tools (P1, P2, P3, P4) installed side by side on a tool installation unit of a press brake, the tool change method comprising: placing a fixing unit configured to regulate a movement of the tool (P1, P2, P3, P4) at a reference position (Pst); moving the plurality of tools (P1,P2,P3,P4) installed on the tool installation unit to one side along an arrangement direction of the tools (P1,P2,P3,P4) on the tool installation unit; bringing the plurality of tools (P1, P2, P3, P4) together at the fixing unit; acquiring, by a control device configured to control an operation of a tool change unit (13UL,13UR) which automatically performs tool change, tool information for each of the plurality of tools (P1,P2,P3,P4) that have been brought together through a device capable of acquiring the tool information, wherein the tool information is information in which a tool ID for identifying the tool is associated with an arrangement order; acquiring, by the control device, layout information indicating information of the tools that should be on the tool installation unit; calculating, by the control device, a total sum of divided lengths of tools that should be on the tool installation unit based on the layout information; when a length from the reference position (Pst) to an end position (Peg) of the plurality of tools (P1,P2,P3,P4) that have been brought together does not coincide with the total sum of divided lengths, determining, by the control device that there is some excess or deficiency of the tool; - acquiring, by the control device, the tool information in which a tool ID is associated with an arrangement order for each of the plurality of tools (P1,P2,P3,P4) that have been brought together; and - controlling, by the control device, the tool change unit (13UL, 13UR) to store the plurality of tools (P1,P2,P3,P4) that have been brought together in the tool storage unit based on the acquired tool information. placing a fixing unit configured to regulate a movement of the tool (P1, P2, P3, P4) at a reference position (Pst); moving the plurality of tools (P1,P2,P3,P4) installed on the tool installation unit to one side along an arrangement direction of the tools (P1,P2,P3,P4) on the tool installation unit; bringing the plurality of tools (P1, P2, P3, P4) together at the fixing unit; acquiring, by a control device configured to control an operation of a tool change unit (13UL,13UR) which automatically performs tool change, tool information for each of the plurality of tools (P1,P2,P3,P4) that have been brought together through a device capable of acquiring the tool information, wherein the tool information is information in which a tool ID for identifying the tool is associated with an arrangement order; acquiring, by the control device, layout information indicating information of the tools that should be on the tool installation unit; calculating, by the control device, a total sum of divided lengths of tools that should be on the tool installation unit based on the layout information; when a length from the reference position (Pst) to an end position (Peg) of the plurality of tools (P1,P2,P3,P4) that have been brought together does not coincide with the total sum of divided lengths, determining, by the control device that there is some excess or deficiency of the tool; - acquiring, by the control device, the tool information in which a tool ID is associated with an arrangement order for each of the plurality of tools (P1,P2,P3,P4) that have been brought together; and - controlling, by the control device, the tool change unit (13UL, 13UR) to store the plurality of tools (P1,P2,P3,P4) that have been brought together in the tool storage unit based on the acquired tool information. - acquiring, by the control device, the tool information in which a tool ID is associated with an arrangement order for each of the plurality of tools (P1,P2,P3,P4) that have been brought together; and - controlling, by the control device, the tool change unit (13UL, 13UR) to store the plurality of tools (P1,P2,P3,P4) that have been brought together in the tool storage unit based on the acquired tool information.