The advantages of silicon on insulator (SOI) technology have been demonstrated in a wide range of applications, which include high-speed and radiation-tolerant CMOS devices, three-dimensional integration and very short channel VLSI circuits [1–3]. However, design and modeling of any new device require a detailed knowledge of electrical properties of used material. It is well known, that conventional characterization techniques used for bulk Si structures can not be directly applied in the case of SOI. A number of electrical characterization techniques suitable for SOI has been reported in the literature [4–6]. In this paper, characterization methods based on the use of SOI gated diode and a combined depletion-mode MOSFET and gated diode structure are presented. Proposed methods are applied to characterize both thick-and thin-film laser ZMR SOI structures.