The microwave and convective drying of capillary porous bulk material has been investigated by various microwave powers, air flow rates and temperatures, particle sizes and moisture conditiones. The microwave power is the main parameter. The air flow rate and temperature have a progressive influence especially by low rates of microwave power but the air is necessary for the transfer of the vaporized water. The air temperature should be the same like the boiling temperature of the liquid. Compared with convective drying, you can realize a reduction of the drying times of 85 ... 90% by using the hybrid process. The lower the particle size the better is the energy dissipation of microwaves because of higher water concentrations. The smallest dimension (height or diameter) of the whole bulk material shouldn＇t be lower than a minimum.