A module with a built-in component is provided which can be produced without a via-forming step. The module with a built-in component 100 includes an insulating sheet substrate 10 which has an upper surface 10a, a lower surface 10b opposed to the upper surface 10b and a side surface 10c which connects these surfaces. At least one wiring 20 extends from the upper surface to the lower surface through the side surface, and an electronic component 32 is disposed within the sheet substrate.