  We obtain an improved determination of the normalization constant of the
first infrared renormalon of the pole mass (and the singlet static potential).
For $N_f=3$ it reads $N_m=0.563(26)$. Charm quark effects in the bottom quark
mass determination are carefully investigated. Finally, we determine the bottom
quark mass using the NNNLO perturbative expression for the $\Upsilon(1S)$ mass.
We work in the renormalon subtracted scheme, which allows us to control the
divergence of the perturbation series due to pole mass renormalon. Our result
for the ${\overline {\rm MS}}$ mass reads ${\overline m}_{b}({\overline
m}_{b})=4201(43)$ MeV.
