In a curable resin composition containing an inorganic filler, the average particle diameter of the inorganic filler is 1 μm or less and the content of the inorganic filler is 50 wt % or less. The curable resin composition can be preferably used for a halogen-free resin substrate and the like having a small load on an environment as a hole-plugging curable resin composition as well as used to provide a hole-plugging build-up printed wiring board having a via-on-via structure (in particular, a stacked via structure) having an excellent crack-resistant property, an excellent insulation/connection reliability, and the like.