Abstract Subsurface wiring level anomalies in VLSI semiconductor devices are extremely difficult, if not impossible to analyze without de-processing the device to expose suspect wiring. Magnetic Force Microscopy (MFM) is a scanning probe technique that requires minimal sample preparation and has the capability to sense magnetic fields in proximity to thin film conductors with high lateral resolution [1]. In this study, multiple VLSI device conductors were intentionally modified and then the magnetic field around the energized conductors was analyzed using MFM. An overview of the technique and results of the magnetic field analysis are discussed.