PURPOSE: To reduce the cost by attaching a soldering position detecting means nearby a work attaching part of a handling mechanism.

CONSTITUTION: A solder tank 11 is fixed on a surface plate 12, and a molten solder liquid 13 is filled inside the solder tank 11. A handling mechanism 14 is installed nearby the solder tank 11 on the surface plate 12. A soldering position detecting means 180 is attached nearby a work attaching part 18b of the handling mechanism 14. In a soldering device 10, when a driving means 15 is used to move a moving part 18 upward, a work 20 is attached easily on the work attaching part 18b at a position being separated from the solder liquid 13 at high temperature. When the moving part 18 is moved downward, the work 20 can be dipped in the flat surface solder liquid 13 without moving the solder tank. Relative positioning between the work 20 and the solder liquid 13 can be executed precisely with the detecting means 180. Therefore, the efficiency of the soldering can be increased.