We report the first detection of OH emission at 1667 MHz from a planetary nebula, IC 4997 (Figure 1). OH emission in satellite line of 1612 MHz was detected already from planetary nebulae not only Vy 2-2 (Davis and Seaquist 1979), but also two IRAS objects which were distinguished from OH/IR stars as planetary nebulae (Pottasch et al 1987). OH observations of IC 4997 have been carried out with the large radio telescope at Nançay, France. Highly resolved optical emission lines were obtained at the Okayama Astrophysical Observatory, Japan.