Contact electrification (CE) at metal-insulator interfaces is a complex phenomenon that has intrigued researchers for centuries, yet it remains inadequately understood. This chapter provides a comprehensive overview of the mechanisms underlying CE at metal-insulator interface, emphasizing the interaction between metals and insulators leads to the formation of potential barriers that govern charge flow, with significant implications for electronic device performance. The theoretical model discussed in this chapter includes the Schottky contact effect and work function difference, to elucidate the principles of charge transfer and the dynamics of electron movement at these interfaces. Advanced techniques such as KPFM are highlighted for their ability to provide nanoscale insights into charge distribution and transfer processes, while the influence from CE to the measurements of AFM is also discussed. By synthesizing recent advancements in the field, this chapter aims to enhance our understanding of CE at metal-insulator interfaces, paving the way for the development of innovative materials and devices that leverage these fundamental principles for practical applications in energy harvesting and electronic technologies.