[en] Suppression of the floating body effects in partially depleted SOI-MOSFETs (silicon-on-insulator metal oxide semiconductor field effect transistors) with and without body contact electrodes has been investigated using nuclear microprobes with currents of 5-250 pA. Transient SOI-MOSFET behavior with and without body contact electrodes during ion irradiation by three-dimensional computer simulation has also been compared with that using nuclear microprobes. The floating body effects were observed in SOI-MOSFETs without body contact electrodes by nuclear microprobe irradiation, while those were suppressed in the SOI-MOSFETs with body contacts