NGC 5548 was observed by BeppoSAX in a single long (8 day) observation from 0.2 to 200 keV. We find (1) the spectral variation of the source is produced by a change of the intrinsic power law slope; (2) a high energy cut-off at E_c= 115^+39_-27 keV with a hint of change of E_c with flux; (3) OVII and OVIII absorption K edges, and a possible blended OVII-OVIII Kα,β emission feature at 0.54^+0.07_-0.06 keV, inconsistent with a purely photoionized gas in equilibrium. We propose that the

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... of the absorbing and emitting gas is ∼ 10^6 K so that both collisional ionization and photoionization contribute.