To provide an information processor capable of easily grasping the general situation of action on a working space.

User's operation on a working space is inputted from an operation information input means 1 and the state of the working space is changed by a working space state changing means 2. When the state of the working space is changed, a state information generation means 3 generates state information indicating the state of the working space and supplies and stores the generated state information to/in a state information storing means 4. A state information extraction means 6 acquires condition information indicating a condition for generating history required by a user through a condition information input means 5 and acquires state information coincident with the condition information from the means 4. A history display means 7 displays the state information acquired by the means 6 in accordance with a specified display format as history. When specification information for specifying a prescribed display element of the history is inputted from a specification information input means 8, an acquisition means 9 acquires corresponding state information from the means 4 and a working space display means 10 displays a corresponding working space.