A plating device and a plating method are provided that are capable of enhancing uniformity in plating on a treatment surface of an object to be treated. The plating device includes: a plating solution bath capable of storing a plating solution and having a first electrode to be immersed in the stored plating solution; a treatment object holding mechanism configured to hold the object to be treated to bring the treatment surface thereof into contact with the plating solution; and a contact disposed in the treatment object holding mechanism and brought into electrical contact with a peripheral edge of the object to be treated so as to make a conductive layer on the treatment surface, which is brought into contact with the plating solution, serve as a second electrode, the contact having a bellows construction or a spring construction movable in a direction facing the object to be treated, and the treatment object holding mechanism being capable of holding the object to be treated while the bellows construction or the like in the contact is in a compressed state. The contact itself is formed as a pliable structure instead of a rigid structure, thereby keeping the contact resistance constant by fluctuation in contact pressure which is controlled to be small even when a slight displacement of the compression direction occurs.