Here we introduce a scanning reflection high-energy electron diffraction technique (Scanning RHEED), that is used to measure simultaneously multiple RHEED intensity variation curves as a function of position, azimuth angle, incident angle or combinations of all three, during epitaxial film growth on a substrate. In this paper, the incident angle dependence of RHEED intensity oscillations is discussed in terms of oscillation amplitude, decay, and phase during SrTiO₃ homoepitaxy on a (100) substrate. A simple way to adjust the incident angle of the electron beam in conventional RHEED systems is also introduced.