To obtain a small multifunction wiring board for power module having a high conductivity by employing an insulation board of sintered silicon nitride and providing a power wiring section and a control wiring section integrally.

The wiring board for power module comprises an insulation board 1 having a thermal conductivity of 40 W/m.K or above where the mean aspect ratio of silicon nitride crystal particles of sintered silicon nitride containing a sintering accelerator, i.e., an oxide of rare earth element (RE2O3) and an oxide of alkaline earth element (RO), by 3-30 mol% in total at RE2O3/RO mol ratio of 0.1-15 is 3 or less, a power wiring section X having a power wiring layer 2 of Cu or Al formed on the surface of the insulation board 1, and a control wiring section Y including an inner wiring layer 9 having sheet resistance of 30 mΩ/(square) formed in the insulation board 1.