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SUMMARY Boron and nitrogen K‐edge spectra for hexagonal boron nitride (h‐BN) were measured by electron energy loss spectroscopy (EELS) at orientations of a momentum transfer q parallel and perpendicular to the c‐axis in order to investigate anisotropic unoccupied states π* and σ*, separately. Differences between intensity profiles for BK and NK spectra are attributed to different transition probabilities at BK and NK edges from Is states to the π* and σ* states. The intensity of the first peak at q∥c in the BK spectrum, which is ascribed to the transition from B‐1s to the Q—2 state in the π* band, is 10 times as large as that in the NK spectrum. Quantitative calculation of transition probabilities for BK and NK spectra at q∥c shows that the contribution of B‐2pz orbital to the Q—2 state is 1–7 times as large as that of N‐2pz. This value suggests that the enhanced peak in the BK spectrum is explained by means of single electron excitations, disregarding the electron‐electron interactions for the exciton reported by several workers. The contributions of 2px and 2py orbitals of B and N atoms to σ* states are also estimated by intensity analysis of BK and NK spectra at q⊥c.

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