The [33.2]2Π1/2,3/2 and A'2Δ5/2 electronic states of the astrophysically relevant yttrium oxide(YO)molecule have been experimentally studied at high resolution for the first time.The YO molecules are produced using the same method as in Part I of this work,i.e.,by corona discharge of oxygen between the tips of two yttrium needles in a supersonic jet expansion.