Imaging mass spectrometry has the advantage of being able to analyze the chemicals on the surface of biological samples such as tissues, hair and teeth while preserving their characteristics. It can visualize the distribution of compounds. For biological samples, e.g., hair, teeth and bone, spatiotemporal data can also be acquired. Imaging mass spectrometry is a technique widely used in medical and clinical research on, e.g., therapeutic effect on cancer, mobility of a drug to a target site or drug compliance. We introduce the latest findings on organic and elemental analysis applying the imaging mass spectrometry to some biological samples as well as its application to epidemiological surveys.