We are interested in the development of novel mass spectrometric apparatus for the in situ and ambient ionization. These instrumental setups will be targeted on the real time, online reaction studies, especially the OPERANDO chemical reaction studies with mass spectrometry and other integrated techniques, which enable the capture of short-lived reaction intermediates. Based on these novel and creative designes, the methods are developed for the elucidation of underlying mechanism of chemical and biological reactions, as well as the high throughput new reaction discovery, which will be applied to the design of new reaction pathways and synthetic methodology.