The voltage–current characteristics of a discharge at atmospheric pressure in a wide range of discharge currents have been numerically studied within a hybrid model for a gas-discharge plasma with a self-consistent description of the heating of a cathode. Segments corresponding to a normal glow discharge, a transition from a glow discharge to an arc discharge, and an arc discharge have been revealed on the voltage–current characteristics. All main parameters of the plasma have been obtained for each of these segments of the voltage–current characteristics of the discharge.