The paper presents the results of experimental and theoretical study of the low current mode of negative corona. The purpose of the study was to find the electron emission mechanism that is responsible for the rise of negative corona pulses. The main idea of the study based on earlier observations that the presence of non-metallic inclusion at the electrode favours the rise of negative corona discharge. For this reason a systematic study of negative corona was carried out also with electrodes, which had coatings of known composition and thickness. The results of the study confirm that the rise of negative corona is controlled by Fowler-Nordheim type of emission, which occurs at the metal-dielectric interface.