A tool storage device is provided inside a rack body arranged on a side of a bending machine in a left-right direction, and includes tool holding units for holding long upper tools. The tool holding units include a stocker linearly provided with tool holding grooves for holding the long upper tools, and a stocker moving unit for advancing and retracting the stocker in a front-rear direction, and horizontally rotating the stocker. The stocker has, as states between which switching can be performed, a first state in which the tool holding grooves are stored in the rack body in an orientation in the front-rear direction, and a second state in which the stocker advances to the outside of the rack body and the tool holding grooves are aligned in the left-right direction along a holder groove of the upper tool holder.