In this paper, a naphthalene (C10H8) thermal cracking model is presented. The model is based on a simple model that takes into account the microwave (MW) plasma thermal influence on naphthalene cracking, accompanying its steam reforming reactions. The temperature level of 1573 K was established for complete C10H8 cracking at 1.75 kW plasma power. High conversion efficiency of C10H8 is achieved varying the air flow rate in the range of 0.6-1.2 m(3)/h. The model approximates the characteristics of the considered MW plasma to thermal plasma in local thermodynamic equilibrium (LTE). Experimental data have good agreement with calculated data at the cited region of the air flow rate and power. Conversion efficiency up to 99.36% was obtained.