It is necessary to evaluate the endurance of tungsten (W) under plasma irradiation to realize the nuclear fusion reactor. The tungsten that has flat surface and amorphous structure is often assumed in the experiment and the simulation in plasma-wall-interaction study. However, from experiments, it has been reported that the sputtering yield for the flat surface W under argon (Ar) irradiation is different from that for the rough (fuzz) surface W. In our previous work, using binary-collision-approximation (BCA) simulation, we calculated the sputtering yield under Ar irradiation onto W target which has “simplified rough surface.” We could obtain the roughness dependence of the sputtering yield, which is coincident qualitatively with the experimental result. In this paper, we also calculated the physical quantities, i.e., sputtering yield, retention rate and mean penetration depth, under the noble (helium, neon, or argon) gas irradiation onto four types of the flat W targets: Amorphous W and BCC W lattices with the crystal orientation (110), (100) and (111). This simulation shows that the W surface structure affects noticeably the physical quantities. From these simulations, we propose that it is necessary to consider the surface form and the crystal structure to evaluate the sputtering phenomena though it has not been considered sufficiently.