Holding jig

A holding jig for holding a planar workpiece and immersing the planar workpiece in a liquid bath in a plating solution of a container, the holding jig comprising:

• a rear member;
• and
• a front member that faces the rear member and has an opening portion,
• wherein the rear and front members are arranged so that the planar workpiece is disposed between the rear member and the front member,
• the planar workpiece has a first surface facing the front member and a second surface facing the rear member,
• the opening portion of the front member faces the first surface of the planar workpiece,
• the rear member, the front member, and the planar workpiece are to be immersed in the plating solution, and
• the first surface of the planar workpiece is partially exposed through the opening portion, wherein the rear member has a plurality of projections formed on a surface of the rear member facing the front member, and
• top surfaces of the plurality of projections contact the second surface of the planar workpiece;
• wherein the projections have an average height of 1 to 3 mm in a cross section of a thickness direction of the rear member;
• wherein a total area of the top surfaces of the projections is between 10% to 40% of an area of the opening portion.