To provide a method of manufacturing a wiring board for reducing curvature remarkably, while maintaining package reliability by controlling the increase in the time of the assembly process of a semiconductor device.

The method of manufacturing a semiconductor device comprises(a) a process for connecting a first semiconductor chip 21 and a second semiconductor chip 21 to a circuit wiring 11, respectively, including two or more holes (14) penetrated from one field to a field of another side, from both sides of a wiring board 1 provided with the circuit wiring 11 in an insulating layer 2 which can be impregnated with an underfill resin 31, and the insulating layer 2; (b) a process wherein the underfill resin 31 is impregnated from one wiring board 1 side; and (c) a process for hardening the underfill resin 31 so that the first and second semiconductor chips 21 and the wiring board 1 may unify.