Over recent decades, analytical chemistry has significantly advanced methodologies for analyzing food, environmental samples, and technological materials, focusing on elemental characterization. Among instrumental techniques, inductively coupled plasma optical emission spectrometry (ICP-OES) has become prominent, requiring sample preparation through acid digestion to transform solids into homogeneous aqueous solutions. This process, typically involving nitric acid (HNO3), hydrochloric acid (HCl), and hydrogen peroxide (H2O2), ensures compatibility for analysis by removing matrix interferences. However, complex or refractory matrices often necessitate stronger reagents, such as sulfuric (H2SO4) or hydrofluoric (HF) acids, increasing preparation times and analytical costs. To overcome these challenges, direct solid sample analysis methods have gained traction, with laser-induced breakdown spectroscopy (LIBS) emerging as a versatile alternative. LIBS facilitates rapid, cost-effective, and nondestructive analysis across diverse applications, including technological materials, hazardous substances, extraterrestrial soils, and deep-water samples. This technique eliminates extensive sample preparation while maintaining accuracy and precision. This chapter highlights the principles and advantages of LIBS, focusing on calibration quantitative analysis. Special attention is given to practical examples in various fields, such as food, geological, and industrial materials. In the case of liquid and slurry samples calibration for quantitative analysis, methods involving encapsulation are discussed. LIBS represents a transformative tool for modern analytical chemistry.