A substrate with a built-in component is constructed such that a resin reliably goes around a clearance provided in a lower portion of the component and is thus filled in without expansion of a clearance in a height direction when various components such as an LW reversal type chip component are to be built in. The substrate includes a component to be embedded in a resin layer, and a land electrode (a component mounting electrode) to which external electrodes of the component are to be bonded, the land electrode being provided with a concave groove extending in a transverse direction through which an uncured resin of the resin layer flows, and the uncured resin of the resin layer flows through the concave groove and sufficiently goes around a lower side of the component so that the resin is well filled in when the component in a mounting state is to be embedded in the resin layer.