A coil structure comprising: a base plate including a coil conductor ; a first core disposed on one main surface side of the base plate; a second core disposed on other main surface side of the base plate; and an insulating member made of an insulating material, wherein the first core includes: a main body part extending in a first direction along a main surface of the base plate; a first foot part extending from the main body part to the second core through the base plate; and a second foot part extending from the main body part to the second core through the base plate at a position such that the coil conductor is sandwiched between the second foot part and the first foot part in the first direction, and the insulating member includes: a bottom wall part interposed between at least the first foot part and the second core ; and a side wall part extending along at least either of the first foot part and the second foot part and interposed between either of the foot parts and the coil conductor ; wherein a heat dissipation material is disposed in a gap between the second foot part and the second core , and the heat dissipation material is made of a material having a higher thermal conductivity than the insulating member . a base plate including a coil conductor ; a first core disposed on one main surface side of the base plate; a second core disposed on other main surface side of the base plate; and an insulating member made of an insulating material, wherein the first core includes: a main body part extending in a first direction along a main surface of the base plate; a first foot part extending from the main body part to the second core through the base plate; and a second foot part extending from the main body part to the second core through the base plate at a position such that the coil conductor is sandwiched between the second foot part and the first foot part in the first direction, and the insulating member includes: a bottom wall part interposed between at least the first foot part and the second core ; and a side wall part extending along at least either of the first foot part and the second foot part and interposed between either of the foot parts and the coil conductor ; wherein a heat dissipation material is disposed in a gap between the second foot part and the second core , and the heat dissipation material is made of a material having a higher thermal conductivity than the insulating member . a main body part extending in a first direction along a main surface of the base plate; a first foot part extending from the main body part to the second core through the base plate; and a second foot part extending from the main body part to the second core through the base plate at a position such that the coil conductor is sandwiched between the second foot part and the first foot part in the first direction, and the insulating member includes: a bottom wall part interposed between at least the first foot part and the second core ; and a side wall part extending along at least either of the first foot part and the second foot part and interposed between either of the foot parts and the coil conductor ; wherein a heat dissipation material is disposed in a gap between the second foot part and the second core , and the heat dissipation material is made of a material having a higher thermal conductivity than the insulating member . a bottom wall part interposed between at least the first foot part and the second core ; and a side wall part extending along at least either of the first foot part and the second foot part and interposed between either of the foot parts and the coil conductor ; <EOS>