A plasma assisted apparatus for organic film deposition, comprising: a plasma chamber, capable of thermally cracking a precursor in the plasma chamber; and a deposition chamber, being channeled with the plasma chamber for receiving the thermally cracked precursor. In an exemplary embodiment, the deposition chamber further comprises a substrate device, being provided for the thermally cracked precursor to deposit thereon to form an organic film. As the plasma chamber is separated from the deposition chamber in the aforesaid apparatus, a low-temperature film deposition process can be used for forming organic films while preventing the substrate device from being bombarded directly by plasma. In addition, as there is a flow guiding device arranged at the outlet of the plasma chamber, the thermally cracked precursor is guided or disturbed and thus is prevented from overly concentrating at the outlet or the center of the substrate device. Thereby, surface roughness as well as uniformity of the organic film can be effectively improved.