  We present the high resolution (R $\approx$ 60000), high signal-to-noise (S/N
$\simeq$ 120) spectroscopic analysis of 12 red giant members of the Galactic
open cluster NGC 6940. We applied Yonsei-Yale isochrones to the color-magnitude
diagram, which suggested an age of 1.1 Gyr for the cluster with a turn-off mass
of 2 M$_{\odot}$. Atmospheric parameters ($T_{\rm eff}$, $log~{\it g}$, [Fe/H]
and $\xi_{t}$) were determined via equivalent widths of Fe I, Fe II, Ti I, and
Ti II lines. Calculated mean metallicity of the cluster is $\langle {\rm
[Fe/H]} \rangle = 0.04\pm0.02$. We derived abundances of $\alpha$ (Mg, Si, Ca),
Fe-group (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn), and $n$-capture (Y, La, Nd,
Eu) elements to be about solar. Light odd-Z elements Na and Al are slightly
enhanced in MMU 108 and MMU 152 by $\sim$0.34 dex and $\sim$0.16 dex,
respectively. Abundances of light elements Li, C, N, O, and $^{12}$C/$^{13}$C
ratios were derived from spectrum syntheses of the Li I resonance doublet at
6707 $\overset{\lower.5em\circ}{\mathrm{A}}$, [O I] line at 6300
$\overset{\lower.5em\circ}{\mathrm{A}}$, C$_{2}$ Swan bandheads at 5164
$\overset{\lower.5em\circ}{\mathrm{A}}$ and 5635
$\overset{\lower.5em\circ}{\mathrm{A}}$, and strong $^{12,13}$CN system lines
in the 7995$-$8040 $\overset{\lower.5em\circ}{\mathrm{A}}$ region. Most carbon
isotopic ratios are similar to those found in other solar-metallicity giants,
but MMU 152 has an unusual value of $^{12}$C/$^{13}$C=6. Evaluation of the
LiCNO abundances and $^{12}$C/$^{13}$C ratios along with the present
theoretical models suggests that all the red giants in our sample are
core-helium-burning clump stars.
