A circuit device and a method for fabrication the same is provided. An insulation resin sheet in which the first conductive layer 3 and the second conductive layer 4 are adhered to each other by insulation resin 2 is used. The first conductive path layer 5 is formed by the first conductive layer 3, the second conductive path layer 6 is formed by the second conductive layer 4, and both of the conductive path layers are connected by multi-layer connecting means 12. Since a semiconductor element 7 is adhered to and fixed on overcoating resin 8 that covers the first conductive path layer 5, a multi-layer connection structure can be achieved by the first conductive path layer 5 and the second conductive path layer 6. Further, the second conductive layer 4 that is made thick can prevent warping from occurring due to a difference in a thermal expansion coefficient.