To enhance the productivity of an offline teaching work by visualizing the working position, path, and the like of an end effector in offline teaching. A robot teaching device, includes: a teaching point marker display unit configured to display, on a GUI, teaching point markers for marking teaching points in a three-dimensional modeling space in which at least a three-dimensional model of a robot including an end effector and a three-dimensional model of a work piece are arranged, the teaching points serving as target passing points of the end effector; a joined path display unit configured to display, on the GUI, a joined path, which is a path connecting successive points among the teaching points to each other; and a changing point marker display unit configured to display, on the GUI, a changing point marker marking a point at which a working state of the end effector changes.