An element-block is defined as a minimum functional unit composed of heteroatoms. The concept of ‘element-block material’ for designing advanced materials was proposed in 2015. In this review, the recent progress in material designs based on this concept is described. From our research, several element-blocks as representative examples are selected, and their roles in each material are explained. Initially, research on the development of ‘designable hybrids’ by employing polyhedral oligomeric silsesquioxane (POSS) is illustrated. Multiple functions of hybrids composed of modified POSS and the significant roles of POSS in bio-related polymeric materials for solving critical problems in conventional19F MR probes and for realizing new sensing technologies are demonstrated. Next, solid-state luminescent materials containing o-carborane and group 13 element-blocks are discussed. The materials’ highly efficient emission in the solid state and their origins are explained. Furthermore, stimuli-responsive luminescent chromism is summarized. The sensing mechanisms and the application of these materials as sensors are presented in this study. In the last part, we mention optically active element-blocks containing chiral P-stereogenic phosphorus. In this review, the characteristics originating from each element-block are explained.