Surface treatment system and workpiece-holding jig

A workpiece-holding jig that vertically holds a sheet rectangular workpiece in a solution contained in a treatment tank, and sets the rectangular workpiece as a cathode, the workpiece-holding jig comprising:

• a frame member that is disposed to surround the rectangular workpiece and includes a conductive upper frame member and a conductive lower frame member electrically insulated from the conductive upper frame member;
• a plurality of conductive first clampers that are supported by the upper frame member, and hold an upper side of the rectangular workpiece;
• a plurality of conductive second clampers that are supported by the lower frame member in a state in which the plurality of second clampers are electrically insulated from the plurality of first clampers, and hold a lower side of the rectangular workpiece;
• a first current-carrying section that supplies current to the plurality of first clampers;
• and
• a second current-carrying section that supplies current to the plurality of second clampers.