The first stable 9-anthryldiphosphene, TbtP=P(9-Anth) (1: Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl, 9-Anth = 9-anthryl), was synthesized and its properties were revealed by spectroscopic and X-ray crystallographic analyses. The weak fluorescence of I was observed in hexane solution.