  The mass and decay constant of the ground state of spin singlet $b \bar{b}$
is calculated by using the QCD sum rules method. This meson is an axial vector
$P$-wave named $h_b(1P)$ meson with $J^P =1^+$. It is found that the mass of
this meson is $(m=9940\pm 37)$ MeV, which is consistent with the recent
experimental data by Belle collaboration.
