Depending on the application of nanoparticles, certain characteristics of the product quality such as size, morphology, abrasion resistance, specific surface, and tendency to agglomeration are important. These characteristics are a function of the physicochemical properties of the nanostructured material and, thus, of the process parameters of the particle synthesis. Because of econimical reasons in large-scale production such as pyrolysis or precipitation processes, nanosized particles are produced not as single primary particles but rather as aggregates or agglomerates. The application properties of these aggregates are strongly affected by the micromechanical properties, which can be measured via nanoindentation. In this study, a flat punch method was used. For the measurements, model aggregates out of sol–gel produced silica with varying primary particle size and strength of solid bonds were used. Generally, the micromechanical properties can be characterized by measuring the micromechanical properties via nanoindentation and be described by different theoretical models.