In this paper, we discuss the lepton structure and the (μ-e mass-difference on the basis of the "muonic charge" model. Some general theorems concerning the lepton structure are demonstrated. For example, it is shown that the form factors of "muonic charge" current and of electric current of charged lepton having anomalous interaction are equal. As a result, this lepton would posses a "muonic moment". It is shown that the anomalous interaction self-energy corresponding to "muonic-charge-muonic moment" interaction is the dominated term and the μ-e mass difference is consistent with the known experimental data of the electromagnatic structure of the eletron.