  Graphene is a truly two-dimensional material with exceptional electronic,
mechanical, and optical properties. As such, it consists of surface only and
can be probed by the well developed surface-science techniques as, e.g.,
scanning tunneling microscopy. This method bridges the gap between the surface
science community and the electronic device community and might lead to novel
combined approaches. Here, I review some of the scanning tunneling microscopy
(STM) and spectroscopy (STS) experiments on monolayer graphene samples. I will
concentrate on graphene samples deposited on insulating substrates, since these
are related to graphene device concepts. In particular, I will discuss the
morphology of graphene on SiO$_2$ and other emerging substrates, some
nanomechanical manipulation experiments using STM, and spectroscopic results.
The latter can map the disorder potentials as well as the interaction of the
electrons with the disorder which is most pronounced in the quantum Hall
regime.
