Quantum geometry in condensed matter physics allows us to understand various geometric properties of the Brillouin zone states, such as the Berry curvature and the quantum metric. Especially in relation to the latter, studies have been observed that show its relationship with superconductivity. Motivated by these investigations, this dissertation aims to investigate the quantum geometric properties of singlet superconductors, such as s-wave and d-wave types, and identify their relation to various electromagnetic responses. We begin by showing the description of these superconductors through mean field theory, subsequently analyzing their quantum metric, which is defined by the overlap of two quasihole states at slightly different momenta. Subsequently, we study the fidelity number, which is defined as the momentum integration of the quantum metric and represents the average distance between neighboring quasihole states. Furthermore, we express this fidelity number as a fidelity marker defined locally at each lattice site, which allows us to observe the effect of non-magnetic impurities on this marker. For s-wave superconductors, we show that electromagnetic responses such as infrared absorption are related to the quantum metric, while on the other hand, the paramagnetic current and the dielectric function are related to the fidelity number, which in turn is determined by the coherence length. On the other hand, for d-wave super-conductors, we observe that their quantum metric shows a singular behavior and that their fidelity number diverges. The most relevant result of this dissertation is that we have discovered that singlet superconductors, described by the BCS mean field theory, exhibit a nontrivial quantum metric, and that for s-wave superconductors the aforementioned electromagnetic responses are directly related to the quantum geometry, which has not been found previous.