To prevent damage, corruption, and maintain the quality of fruits, vegetables and food their long-term protection is essential. There are several methods for preserving foods including canning, freezing and drying. Among these methods, drying, is an effective and practical method for reducing post-harvest food losses, especially for developing countries that have poor facilities for low temperature processes. In this study, freeze drying combined with electrohydrodynamic drying (EHD) is examined as an improved method for drying mushroom slices. At first the pre experiments were conducted in order to find three optimum intensities.The effects of three levels of intensity3.04, 3.8 and 4.56 kV/cm (15.2, 11.4 and 9.12 kV at 5, 3 and 2 cm, respectively) on drying time, water effective diffusion coefficient, energy consumption and quality characteristics of dried mushroom slices with EHD and electrohydrodynamic combined vaccum freeze drying (EHFD) systems were investigated and compared with vaccum freeze drying (VFD). ANOVA showed that there were significant differences between EHD, EHFD and VFD treatments for all of the studied responses. Results indicated that EHFD had less drying time, more the effective moisture diffusion coefficient, average drying rate and energy consumption than EHD treatments with the same intensity. EHFD has less energy consumption than vacuum freeze drying therefore as a strategy to reduce energy consumption in industrial drying is recommended. In the second part of this study, effect of electric field intensity on qualitative properties (rehydration, percentage of surface reduction, shrinkage and color difference) of dried mushroom slices with EHD and EHFD systems were studied. Results showed an increment in rehydration of EHFD compared to EHD were due to the vacuum freeze drying. EHFD had significant differences compared to EHD treatments with same intensity for ?b and ?E responses of dried mushrooms slices. for both EHFD and EHD treatments, ?E response decrease with reducing the intensity of the electric field. The result showed for EHD and EHFD, as drying time was lower the percentage of surface reduction was more. There was no significant difference between the shrinkage percentage of EHD and EHFD treatments. In the third part of this study, the effect of electric field intensity was investigated on the amount of free water present in dried mushroom and on specific heat curve obtained from diffrential scaning calorimetry in the range of -20 to 50 °C in EHD and EHFD and were compared with VFD. Cooling thermograms indicated absence of freezable water for samples were dried with EHFD and EHD approaches and thus maintaining dried mushroom slices with both ways can be done satisfactory. EHFD 11.4 kV and 3 cm gap (3.8 kV/cm) was chosen as the optimum treatment. Then to evaluate effect of ultrasound pretreatment power at 40 KHz and 3 minutes was applied before the optimum treatment and was not more favorable. Keywords: Electrohydrodynamic (EHD); Vaccum freeze drying (VFD); Drying kinetics; Energy consumption