The aim of this work is to understand the granular behavior of metal powder during the spreading phase of the LBM process in order to study the effect of powder properties and process parameters on the quality of the layer deposited before laser fusion. This is a numerical work performed with simulations based on the discrete element method where each powder grain is simulated. The numerical model takes into account different interactions such as repulsion, dissipation, friction and adhesion that occur when there is contact between two bodies. The powder grains are assumed to be perfectly spherical. The surface roughness of the plate and spreader is taken into account in the simulations as it has a significant impact on the powder bed spreading. The effect of material parameters such as friction and adhesion is studied. The influence of the spreading speed is also studied. The results show that different friction values give the same results on the final properties of the powder bed while adhesion plays a significant role. Finally, lower spreading speed result in a better powder bed.