A circuit board includes an insulating part including insulating layers, metal layers disposed on the insulating layers, vias each passing through at least one insulating layer among the insulating layers and connecting together at least two metal layers among the metal layers; a first thermally conductive structure including a thermally conductive material, at least a part of the thermally conductive structure being inserted into the insulating part, a first via having one surface contacting the first thermally conductive structure, a first metal pattern contacting another surface of the first via, a first bonding member connected to the first metal pattern, and pads to which a first electronic component is connected on an outermost surface of a metal layer disposed on an outermost surface of the insulating part, the pads being at least in a first region and a second region having a higher temperature than the first region.