Detached eclipsing binaries are remarkable systems to provide accurate fundamental stellar parameters. The fundamental stellar parameters and the metallicity values of stellar systems are needed to deeply understand the stellar evolution and formation. In this study, we focus on the detailed spectroscopic and photometric studies of three detached eclipsing binary systems, V372,And, V2080,Cyg, and CF,Lyn to obtain their accurate stellar, atmospheric parameters,and chemical compositions. An analysis of light and radial velocity curves was carried out to derive the orbital and stellar parameters. The disentangled spectra of component stars were obtained for the spectroscopic analysis. Final teff, logg, $xi$, vsini, parameters and the element abundances of component stars were derived by using the spectrum synthesis method. The fundamental stellar parameters were determined with a high certainty for V372,And, V2080,Cyg ($sim$$1-2$%) and with an accuracy for CF,Lyn ($sim$$2-6$%). The evolutionary status of the systems was examined and their ages were obtained. It was found that the component stars of V2080,Cyg have similar iron abundance which is slightly lower than solar iron abundance. Additionally, we showed that the primary component of CF,Lyn exhibits a non-spherical shape with its 80% Roche lobe filling factor. It could be estimated that CF,Lyn will start its first Roche overflow in the next 0.02,Gyr.