The Belle II experiment follows the path defined by the Belle and BaBar experiments, both of which started taking data about 20 years ago at the B-factories KEKB (Tsukuba, Japan) and PEP-II (SLAC, USA), respectively. Until now all measurements performed at B-factories are in agreement with the Standard Model; nowadays, however, there is compelling evidence for New Physics beyond the Standard Model from various sources. For this reason KEK has decided to upgrade the existing KEKB accelerator to deliver a 40 times higher peak luminosity which will allow to record a data sample 50 times larger with respect to its predecessor Belle. With such a data set, Belle II will be able to measure the Cabibbo-Kobayashi-Maskawa matrix with unprecedented precision and explore flavor physics in the beauty, charm and tau sectors.

Belle II has also a unique capability, thanks to a new specialized trigger, to search for low-mass New Physics candidates. The Belle II experiment has recently started its data taking at the Upsilon(4S) resonance, and has recorded a data sample of about 6/fb of e+e- collisions. In this seminar, we will review the Belle II detector, the results of the first run and the physics prospects.