In this paper, a nanosheet field effect transistor (NSFET) which surrounds gate from all sides with two stack channels as a label free biosensor has been proposed and investigated by using visual TCAD tool. A nano-cavity (18 nm) is inserted between the channel and gate of nanosheet FET to immobilize the biomolecules. The electrical characteristics of the biosensor are examined in relation to various biomolecules, and it is found that the suggested biosensor is sensitive to both charged and neutral biomolecules. For each of the following materials, a change in current is noted as a result of a change in gate capacitance caused by a distinct biomolecule: (k =1), (k =2), (k =5), and (k=10). The threshold voltage (Vth), current switching ratio (Ion/Ioff), and subthreshold swing (SS) are used to study the sensitivity variation of biosensors to both charged and neutral biomolecules. For biomolecules (k=10), sensitivity is higher than for (k=1, 2, and 5).