It is shown that the conventional mesons and the lowest glueball state can be reasonably described within a simple relativistic quantum-field model of interacting quarks and gluons under the analytic confinement by using a path-integral approach. The ladder Bethe-Salpeter equation is solved for the meson
and glueball (gg) spectra. A minimal set of parameters (the quark masses mf, the coupling constant αs and the confinement scale Λ) is used to fit the latest experimental data. In spite of the simplicity, the model provides a reasonable framework to estimate the decay constants fπ and fK as well as the non-exotic meson and glueball masses in a wide range of energy up to 10 GeV.