A circuit board including a first patterned metal layer and a second patterned metal layer is provided. The first patterned metal layer has metal blocks and spiral structures. A gap is kept between any two adjacent metal blocks. Each of the spiral structures is electrically connected between any two adjacent metal blocks. The second patterned metal layer is disposed beside the first patterned metal layer and has jumper segments. Each of the jumper segments has a first end and a second end opposite to the first end. Each of the spiral structures has an outer end and an inner end. The outer end is connected to one of the two adjacent metal blocks. The inner end is electrically connected to the first end of one of the jumper segments, and the second end of the jumper segment is electrically connected to the other one of the two the metal blocks.