This work reports the dark current density-voltage (J-V) characteristics and electric field profile of InAs photodiode with 100μm × 1μm cross sectional area at a temperature of 300K. The device structure was simulated using 2D SILVACO software and the model was used to determine all the optimum material physical parameters based on the parameters reported in other literatures. Dark current mechanisms, which include drift-diffusion current, generation-recombination current, trap-assisted tunneling current and band-to-band tunneling current, were incorporated into the ATLAS electrical characteristics model. Simulated dark current results were compared with the experimental results that were obtained from InAs photodiodes fabricated from molecular beam epitaxy (MBE) and metal organic vapor phase epitaxy (MOVPE) grown InAs wafers. Good agreement is found between the simulation and experimental results.