A circuit board includes a first capacitor that includes a first dielectric layer, a first conductor layer disposed on a first surface of the first dielectric layer, and a second conductor layer disposed on a second surface of the first dielectric layer opposite to the first surface, a first insulating layer that is bonded to the first surface side with a first adhesive layer and has a higher elastic modulus than the first adhesive layer, and a second insulating layer that is bonded to the second surface side with a second adhesive layer and has a higher elastic modulus than the second adhesive layer.