抄録
Let $¥mathscr{F}$ be a C∞-foliation on a compact C∞-manifold M. We consider the group of all leaf preserving C∞-diffeomorphisms of (M, $¥mathscr{F}$) which are isotopic to the identity through leaf preserving C∞-diffeomorphisms. Then we show that the group is simple if and only if all leaves of $¥mathscr{F}$ are dense.