1. A device for generating an operating procedure manual for software including a captured image of a screen displayed by the software, the device comprising: an image acquiring hardware unit for acquiring a plurality of captured images of a plurality of screens displayed by the software in response to a plurality of operations with respect to the software; an information acquiring hardware unit for acquiring hierarchical structure information indicating the hierarchical structure of a plurality of objects displayed by the software, and acquiring appearance information indicating that, in response to an operation on one object among the plurality of objects, another object different from the one object has appeared; a tree structure generating hardware unit for generating, in response to the hierarchical structure information, a tree structure including a plurality of nodes corresponding to the plurality of objects, respectively, and a plurality of links combining two nodes among the plurality of nodes having a parent-child relationship; an adding hardware unit for adding appearance information to a link between the node corresponding to the one object and the node corresponding to the other object among the plurality of links; a dividing hardware unit for dividing the plurality of captured images into a plurality of captured image groups so that a captured image acquired in response to an operation on the one object and a captured image acquired in response to an operation prior to or subsequent to the operation on the one object belong to separate captured image groups, respectively, if a link with the added appearance information is passed through in the tree structure when a plurality of nodes corresponding to the plurality of objects are scanned in the order of the operations with respect to the plurality of objects; and a generating hardware unit for generating an operating procedure manual including, for each captured image group, a captured image belonging to that captured image group.