As an application of microwave engineering, the new technology of concrete decontamination and decommissioning using microwave energy has been recently developed. The temperature and pore pressure within the concrete are studied theoretically in this paper. The heat and mass transfer within the porous concrete, coupled with temperature dependent dielectric property are investigated. The effects of microwave frequency (f), microwave power intensity (Q_0ave), concrete porosity (φ) on the temperature and pore pressure distributions and their variations are fully discussed. The effects of the variation of complex dielectric permittivity (ε ) and presentation of different steel reinforcements are also illustrated.