An action editing window (200) is formed as a time table of a two-dimensional time line style, made up by a horizontal time axis and a vertical channel. Within the time line table, respective constituent elements of an action of a robot, such as a time ruler (201), a keyframe channel (202), a motion channel (203), a sound channel (204) or an LED operation channel (205), are chronologically displayed. A user is able to edit as synchronization between the respective components of the action is checked. This supports the creation and the editing of a series of commands and data stating a pattern of robot movements.