An offline teaching device has a calculation unit which calculates a second position of a second tool on a work line which is separated by a predetermined distance from a first position of a first tool on the work line, calculates a workpiece position where the first tool in the first position contacts or adjoins the workpiece, and calculates a workpiece position and posture such that the second tool in the second position contacts or adjoins the workpiece by changing the posture of the workpiece from the workpiece position with respect to the first tool, while maintaining the work posture of the first tool, and has a generation unit which generates a robot teaching position based on the position and posture of the workpiece and the holding position of the workpiece, and generates a program such that the first tool and the second tool pass along the work line.