A novel method has been employed to study chemical-vapour-deposited (CVD) diamond surfaces using high-resolution electron microscopy (HREM) without thinning the specimens. The CVD diamond used for the HREM study was directly deposited onto molybdenum grids by microwave plasma-assisted CVD. The HREM images reveal a thin amorphous layer with an average thickness of about 0.8-1.2 nm on the as-grown diamond surface, whereas the average thickness of the surface amorphous layer is decreased to less than 0.4-0.5 nm for samples annealed in air following deposition. When the samples annealed in air are exposed to a hydrogen plasma for 10 min, a distinct damaged layer on the diamond surface is observed. The HREM study demonstrates that this damaged layer consists of an amorphous phase and small diamond bumps, with a thickness of about 1.5-2 nm. The experimental results also illustrate that transmission electron microscopy (TEM) is convenient and effective for the characterization of the surface or near-surface structural features of polycrystalline thin films as long as the grains can be grown on TEM grids.