The radiation effects on a multi-nanosheet tunneling-based field effect transistor (NS-TFET) were investigated for a 3-nm technology node using a three-dimensional (3D) technology computer-aided design (TCAD) simulator. An alpha particle was injected into a field effect transistor (FET), which resulted in a drain current fluctuation and caused the integrated circuit to malfunction as the result of a soft-error-rate (SER) issue. It was subsequently observed that radiation effects on NS-TFET were completely different from a conventional drift-diffusion (DD)-based FET. Unlike a conventional DD-based FET, when an alpha particle enters the source and channel areas in the current scenario, a larger drain current fluctuation occurs due to a tunneling mechanism between the source and the channel, and this has a significant effect on the drain current. In addition, as the temperature increases, the radiation effect increases as a result of a decrease in silicon bandgap energy and a resultant increase in band-to-band generation. Finally, the radiation effect was analyzed according to the energy of the alpha particle. These results can provide a guideline by which to design a robust integrated circuit for radiation that is totally different from the conventional DD-FET approach.