A high frequency wiring board having a high frequency transmission line having a signal conductor line formed on the surface of a dielectric board and a grounding layer formed inside or on the reverse surface of the dielectric board parallel to the signal conductor line, and a connecting terminal portion provided at a terminal end of the high frequency transmission line and including connecting grounding conductors formed with spacing on both sides of the signal conductor line and through conductors for connecting the connecting grounding and the grounding layer. The distance between the through conductors and an end side surface of the dielectric board is not more than 0.3 times the signal wavelength, in the dielectric board, of a high frequency signal.