A wiring substrate (1) comprises an insulating base (10) with connection holes (11), buried conductors (12) provided in the connection holes (11) without reaching a rear surface of the insulating base (10), and wiring layers 14 connected to the buried conductors (12). The buried conductors (12) thicken the wiring layers (14), and can form aligning parts (110) on the rear surface of the connection holes (11) to be used for three-dimensional mounting structure. Each wiring layer (14) includes thin terminals (14A), wirings (14B) and thick electrodes (14C). Not only the terminals (14A) and wirings (14B) but also the buried conductors (12) are raised by the same manufacturing process. A semiconductor element (2) is attached to the electrodes (14C) of the wiring substrate (1).