We found current injection‐stimulated electron emission from n‐type diamond (001) surfaces with negative electron affinity (NEA) and band conduction, while no emission was observed from heavily phosphorous‐doped n+‐type diamond (111) surfaces with NEA and hopping conduction even though the injected current level was four to five orders of magnitude higher than that of the (001) case. Sweeping the potential of the collector electrode implies that electrons are emitted mainly from the positively biased electrode side, where the upward‐band bending should be reduced. These results support the intrinsic upward‐band bending model of the n‐type diamond surfaces with NEA, which was previously indicated by photoelectron emission experiments and theoretical prediction.