[en] The dependence of the sputtering yield and efficiency on the angle of incidence has been calculated using exact methods for treating half-space problems. The yield is found to increase with angle of incidence and to pass through a maximum value around 800 to 850. The efficiency increases monotonically with angle of incidence and does not exhibit a maximum except at 900. The results which are for self-sputtering and employ hard-sphere scattering agree qualitatively with experimental results. (author)