Provided is a method for manufacturing a part built-in substrate, which made highly reliable by preventing such a short as might otherwise be caused by the spread of solder or a conductive adhesive. In the method, a land region (3a) to be connected with a circuit part (6) and a wetness preventing region (4) to enclose the land region are formed over one principal face of a metal foil (1). A terminal electrode (6a) of the circuit part (6) is electrically connected with the land region (3a) by means of solder (5), and an unset resin (7) is contact-bonded over the metal foil (1) and the circuit part, thereby to form the resin layer (7) having the circuit part buried therein. After this, the metal foil (1) is worked to form a wiring pattern (1b). The wetness preventing region (4) is so made of either a region having roughed or oxidized one principal face of the metal foil (1) or a metal having a poor solder wettability as may have a poorer solder wettability than that of the land region (3a).