ROBOT TEACHING DEVICE FOR WARNING OR CORRECTING POSITIONAL DEVIATION OF TEACHING POINTS OR TEACHING LINE

A robot teaching device includes a processing unit for performing processing to warn or correct positional deviation of teaching points or teaching lines. The processing unit includes a teaching position acquisition unit for acquiring four or more teaching positions from a set of target teaching points or a set of target teaching lines, a normal vector calculation section which calculates a normal vector satisfying the set of teaching positions, a distance calculation section which calculates a distance between two teaching positions most distant in the normal vector direction from among the set of teaching positions, and a first warning command section which issues a command, based on a distance between the two teaching positions which are most distant, to warn that the teaching points or teaching lines corresponding to the teaching positions have deviated from an actual plane of a workpiece.