BeppoSAX observed the Seyfert 1 galaxy NGC 3783 for \sim 5 days from 1998 June 6 to 1998 June 10 .
The average flux during the observation was F _ { 2 - 10 keV } \sim 6 \times 10 ^ { -11 } erg cm ^ { -2 } s ^ { -1 } .
The long exposure provided a very high quality spectrum that exhibits all the typical features of Seyfert 1s .
The high energy cut-off of the intrinsic continuum , at E _ { c } = 340 \pm ^ { 560 } _ { 107 } keV , was detected for the first time in this object .
During the observation the source showed modest flux variations ( \sim 20 % in 2-10 keV ) and spectral variability that can be completely explained by a change of the intrinsic slope \Delta \Gamma \sim 0.1 .
NGC 3783 is one of the few Seyfert 1s that exhibits a soft emission component in the BeppoSAX spectrum .
This soft excess is well reproduced by a black body component with temperature kT \sim 0.2 keV .
A warm absorber is also required to fit the soft X-ray spectrum .
Both reprocessing features , the Compton reflection hump and the Fe emission line , were detected in our observation .
In addition to a narrow iron line ( as observed by Chandra ) a broad component with \sigma = 0.72 \pm ^ { 1.28 } _ { 0.27 } keV and EW=115 \pm 76 eV , is required to fit the line .
The observed Compton hump and the Fe line are well reproduced with the ionized ( \lg \xi = 2.73 \pm ^ { 0.04 } _ { 0.05 } ) disc reflection model of Ross & Fabian .
In this case the soft excess observed below 2 keV can be accounted for by the disc emissivity and no additional soft X-rays component is required to fit the spectrum .