The effects of microwave irradiation on drying rate and mechanical strength of a particle layer solidified by drying were examined for a packed-bed sample of glass particles wetted with gelatin solution as a model of casting mould manufacture. Overall drying time was remarkably shortened by microwave irradiation in comparison with convective drying alone. Mechanical strength of the dried sample depended only on temperature during drying for samples with mean moisture content of 0.01-0.02 kg-water/kg-dry solid, suggesting that the main effect of microwave irradiation on solidification by drying is brought about by a temperature increase in the material.