  Optical $UBVRI$ photometry and medium resolution spectroscopy of the type Ib
supernova SN 2009jf, during the period $\sim -15$ to +250days with respect to
the $B$ maximum are reported. The light curves are broad, with an extremely
slow decline. The early post-maximum decline rate in the $V$ band is similar to
SN 2008D, however, the late phase decline rate is slower than other studied
type Ib supernovae. With an absolute magnitude of $M_{V} = -17.96\pm0.19$
magnitude at peak, SN 2009jf is a normally bright supernova. The peak
bolometric luminosity and the energy deposition rate via $^{56}$Ni
$\rightarrow$ $^{56}$Co chain indicate that $\sim {0.17}^{+0.03}_{-0.03}$
M$_{\odot}$ of $^{56}$Ni was ejected during the explosion. He\,I 5876 \AA\ line
is clearly identified in the first spectrum of day $\sim -15$, at a velocity of
$\sim 16000$ km sec$^{-1}$. The [O\,I] 6300-6364 \AA\ line seen in the nebular
spectrum has a multi-peaked and asymmetric emission profile, with the blue peak
being stronger. The estimated flux in this line implies $\ga 1.34$ M$_\odot$
oxygen was ejected. The slow evolution of the light curves of SN 2009jf
indicates the presence of a massive ejecta. The high expansion velocity in the
early phase and broader emission lines during the nebular phase suggest it to
be an explosion with a large kinetic energy. A simple qualitative estimate
leads to the ejecta mass of M$_{\rm ej} = 4-9$ M$_\odot$, and kinetic energy
E$_{\rm K} = 3-8 \times 10^{51}$ erg. The ejected mass estimate is indicative
of an initial main-sequence mass of $\ga 20- 25$ M$_\odot$.
