Black phosphorus (BP) has a puckered honeycomb structure with a tunable bandgap (direct bandgap from 0.3 eV (bulk) to 2.0 eV (monolayer)), where each layer is held together by a weak van der Waals interaction. With its high surface to volume ratio, tunable direct bandgap, excellent electrical and optical properties, BP is expected to greatly contribute to the improvement in nanotechnology. In previous studies, the properties of BP were studied using different characterization methods including transmission electron microscopy and scanning electron microscopy (SEM) and various nanoscale devices were fabricated by electron beam lithography (EBL) process. Thus widely used technologies that utilize electron beam (e-beam) in semiconductor fields imply that discovering the influence of electron-beam irradiation on BP would attribute to better understanding and make use of full potential that BP contains. In our experiment we have employed EBL equipment in order to irradiate e-beam onto BP flakes with precisely controlled beam intensity and area dose. As BP tends to degrade rapidly with the presence of oxygen and water, the vulnerability of BP under e-beam irradiation was also investigated with increasing exposure time under air condition. The mechanically exfoliated BP flakes were irradiated with e-beam after storing each sample in air ambient for different periods of time. It was found that the degradation of BP under e-beam irradiation is highly dependent on the degree of oxidation (air exposure time). The surface morphology was observed in situ by SEM while e-beam was irradiated inside EBL chamber while optical and electrical properties of the BP samples were analyzed using Raman spectroscopy and electrostatic force microscopy, respectively. Realizing the role of e-beam, accurate results can be obtained from further researches on BP. Further results and discussion will be presented in detail.