An electrical apparatus for inactivating microorganisms in saline water was designed. A continuous AC electric field (20 kHz, 14 kV/cm) was applied to 0.1% saline water containing Escherichia coli in order to examine the inactivation effect of the electrical apparatus. After the electric treatment, a reduction of 5 logarithmic orders was observed for E. col! when the final process temperature was controlled at 74degreesC. The temperature was maintained constant by alternating saline concentration with different electric field intensities. A higher electric field at the same process temperature produced a larger decrease of E coli. Further, a higher process temperature at the same electric field also decreased the number of cells. It was concluded that high electric field combined with high temperature plays an important role in inactivation in a short time treatment. (C) 2002 Elsevier Science Ltd. All rights reserved.