The invention provides a method of manufacturing a printed circuit board. The printed circuit board (100) has a conductor layer (ground layer (70)), a signal layer (25) having a signal line (20) provided so as to oppose the conductor layer (ground layer (70)), and an insulating resin layer (60) disposed between the conductor layer (ground layer (70)) and the signal layer (25), the insulating resin layer (60) has voids in an overlapping location, in a plan view, with the signal line (20), and the voids (40) are communicated with the outside of the printed circuit board (100).