Based on the moment characterization of the beam pointing stability proposed by Morin et al., the pointing stability of flattened Gaussian beams (FGBs) is studied. The analytical expression for the misalignment factor of FGBs is derived and a comparison with the approximate result is made. The effect of relative transverse and angular shifts on the misalignment factor is analysed. The validity of the exact and approximate expressions is discussed with illustrative numerical examples. The pointing stability of Gaussian beams and truncated plane waves is also studied, and treated as the spatial cases of FGBs.