PURPOSE: To shorten process and also to enhance reliability without causing any damage to core by inserting concurrently solder sleeve into which the tip of cable is inserted into a plural row of connector terminals, and by soldering them by hot air.

CONSTITUTION: The cable 1 is aligned by the alignment tool 2 and then formed at the pitch between the connector terminals. Then, the cable is cut into a fixed length, the tip of the cut cables is burned by a skin burner to peel off its skin, the tip of each core is bent and then inserted into the solder sleeve 3, and furthermore the solder sleeve is concurrently inserted into the terminal of the connector 4. Then, the alignment tool 2 is removed, and then hot air is applied to the terminal portion of the connector to heat, whereupon the solder inside the sleeve 3 is melted and thus the cable core is soldered to the terminal. Thus, the operational process can be greatly shortened, soldering is made as per forming clearly, and relaibility can be raised.