To provide a long-sized metallic bar stripe-plating method capable of subjecting the long-sized metallic bar to stripe plating of solder, etc. with high accuracy and high quality and an apparatus therefor.

The long-sized metallic bar plating apparatus 10 has a plating liquid supply device 100 for supplying a plating liquid to a plating tank 11. This plating liquid supply device 100 is internally segmented by a partition plate 102 to a main plating liquid supply tank 103 having a pump means 105 for supplying the plating liquid to the plating tank 11 and an auxiliary plating liquid supply tank 104 for supplying the plating liquid to the main plating liquid supply tank 103. The auxiliary plating liquid supply tank 104 has a pump means 109 for supplying the plating liquid from the auxiliary plating liquid supply tank 104 to the main plating liquid supply tank 103 in such a manner that the plating liquid in the main plating liquid supply tank 103 flows out to the auxiliary plating liquid supply tank 104 beyond the partition plate 102 at all times.