Numerous inversion schemes have been developed to delineate both geological structures and depths of the sedimentary basin from the observed Bougeur gravity data either in spatial- or frequency-domain. In the present study we attempted to analyze and evaluate the 'Oldenburg's inversion approach', one of the most common spectral layered-earth inversion schemes, with applications to both synthetic and real data sets using a kind of sequential multi-dimensional inversion strategy. Inversion of the created synthetic data was first performed to determine how accurate and sensitive of such a spectral inversion approach would be for both simple and complicated geometric layered-density models. Inversion of the observed data at Esh El-Mallaha area, one of the most promising Southwestern Gulf-of-Suez hydrocarbon basins with faulted basement in Egypt, was then performed to examine the applicability of such a spectral inversion approach to obtain plausible layered-density models which can be correlated with the available stratigraphic-control well results.