A plating apparatus including a thief electrode that can be suitably maintained is provided. The plating apparatus includes a substrate holder holding a substrate, a thief electrode supporter supporting a thief electrode to be disposed outside the substrate, a plating tank configured to immerse the substrate in a plating solution for applying an electroplating treatment, a thief electrode maintenance tank configured to perform maintenance of the thief electrode, and a transport module configured to transport the thief electrode supporter to the plating tank and the thief electrode maintenance tank.