PURPOSE: To effectively correct a defective soldering place by storing position data of a defective place on inspecting quality of soldering and by applying marking agent consisting of luminous paint to a specified position of a defective place by sweeping a dispenser.

CONSTITUTION: The state of soldering is recognized by an automatic soldering inspecting device of a pre-process, and position data of a pad 21 of a pad 2 which is not soldered is taken in a controller 7. The controller 7 controls a dispenser 8 attached to a robot 6 based on position data of the pad 21, luminous paint 5 is applied to a specified position on a substrate 1 and a defective place is indicated. The substrate 1 is fixed to one place, illumination is put out or dimmed, after a defective place has been recognized illumination is returned to the former condition and soldering defective is modified. Thereby, defective is corrected efficiently and surely without overlooking.