A program correcting device comprises an executing part which executes a simulation of operation of the robot based on an operating program, a calculating part which calculates a variation with time of a TCP speed from the simulation results, an evaluating part which evaluates a pattern of the calculated variation with time if a minimum value of the TCP speed during the calculated variation with time is a predetermined lower limit value or less, a selecting part which selects a correction scheme of the operating program for increasing the minimum value of the TCP speed from a plurality of correction schemes, in accordance with the evaluation results of the pattern of the variation with time, and a correcting part which corrects the operating program in accordance with the selected correction scheme.