To provide a plating device to achieve the partial plating while continuously carrying a lead frame bar in which no plating leak is generated from a rear side.

A pressing jig 130 to press a surface opposite to a surface to be plated of a lead frame 110 is provided with a belt 131 to be moved along a lead frame bar 110A in a plating area to the carriage of the lead frame bar, and a holding part 134 to hold the belt part along the lead frame bar in the plating area against the lead frame side, the belt is provided with a suction hole 132 at the specified position corresponding to each lead frame, and a recessed part to form a hollow part 135 for suction in contact with the belt in pressing the belt on the belt side of the holding part, the lead frame is sucked to the belt side through the hollow part for suction and the suction hole in the belt, and the lead frame is pressed against the masking jig side by the belt.