Our research utilizes magnetic detection based on quantum phenomena to explore fundamental questions in condensed matter physics. We delve into topics such as quantum materials, oxide electronics, superconductivity, and the behavior of systems near criticality. Our approach involves developing and employing a local magnetic sensor to map the spatial distribution of electronic properties. The scanning SQUID offers exceptionally high magnetic sensitivity, capable of detecting minute levels of conductivity, superconductivity, and magnetism, with high spatial resolution.