Shibata, K. JACoW Publishing Geneva, Switzerland SuperKEKB is an ambitious new collider presently being commissioned. In 2019 the vertical IP beta function will be squeezed towards the design value of ~300 micron. Achieving the target value of the specific luminosity is one of the challenges. Another concern is the detector background, e.g. due to beam-beam tails or due to top-up injection. An international collaboration participates in the SuperKEKB beam commissioning. SuperKEKB is an important demonstrator for proposed future high-energy circular colliders like CEPC and FCC-ee.