To suppress generation of dispersion by calculating a position deviation, generated by changing an attitude, by inputting difference information between a robot tip end position in a basic attitude and a robot tip end position in a changed attitude.

A target coordinate value set to a robot controller is changed without moving a robot so that it indicates a jig 22 for a support target even in a condition changing an attitude. By indicating the jig 22 for a support target by a robot tip end position 21' in a changed attitude, a difference between P0=(X0, Y0, Z0) which is a robot relatively measured position 24 first measured and P1=(X1, Y1, Z1) which is a robot relatively measured position 24' measured by changing an attitude is calculated as P1-P0=(X1-X0, Y1-Y0, Z1-Z0). Here, P1-P0 expresses a position deviation 25 from a target position of an actual robot tip end in the case of changing the attitude.