A robot performs, after i-th (i is a natural number) work, i+1-th work different from the i-th work and performs, after j-th (j is a natural number satisfying j≠i) work, j+1-th work different from the j-th work. The robot performs the i+1-th work after the i-th work without changing information concerning correction in a joint of the robot during the i-th work, performs robot calibration after the j-th work, and performs the j+1-th work after performing the robot calibration.