We developed a novel spintronic device Spin-transfer-Torque Switching-MOSFET (STS-MOSFET) which offers non-volatile memory and transistor functions that are CMOS compatible and have high endurance and a fast write time. STS-MOSFETs with Heusler alloy (Co2FeAl0.5Si 0.5) were prepared and reconfigurability of the novel spintronics-based STS-MOSFET was successfully realized in the transport properties. The transistor properties such as drain current as a function of drain voltage, sub-threshold and carrier mobility properties are not hindered by ferromagnet/tunnel source/drain electrodes. The device showed clear magnetocurrent (MC) and write characteristics with the endurance of over 10 5 cycles. Moreover, the area and speed of million-gate spin field programmable gate arrays (FPGAs) are numerically benchmarked with CMOS FPGA for 22, 32, and 45 nm technologies including a 20 transistor size variation. We showed that the performance of spin FPGA becomes superior to that of conventional CMOS FPGA as transistor size decreases and MC ratio increases. The overall properties of the STS-MOSFETs show great potentialities for future reconfigurable integrated circuits based on CMOS technology.