  Differences in chemical composition among main sequence stars within a given
cluster are probably due to differences in their masses and other effects such
as radiative diffusion, magnetic field, rotation, mixing mechanisms, mass loss,
accretion and multiplicity. The early type main-sequence members of open
clusters of different ages allow to study the competition between radiative
diffusion and mixing mechanisms. We have analysed low and high resolution
spectra covering the spectral range 4500 - 5840 Angs. of late B, A, and F type
members of the open Cluster M6 (age about 100 Myr). The spectra were obtained
using the FLAMES/GIRAFFE spectrograph mounted at UT2, the 8 meter class VLT
telescope. The effective temperatures, surface gravities and microturbulent
velocities of the stars were derived using both photometric and spectral
methods. We have also performed a chemical abundance analysis using synthetic
spectra. The abundances of the elements were determined for C, O, Mg, Si, Ca,
Sc, Ti, Cr, Mn, Fe, Ni, Y, Ba. The star-to-star variations in elemental
abundances among the members of the open cluster M6 were discussed.
