Feuilletages singuliers de codimension un, Groupo\"{i}de de Galois et   int\'{e}grales premi\`{e}res
  We study the Galois groupoid of a holomorphic singular codimension one foliation. Geometric and algebraic caracterisations using Godbillon-Vey sequences and classical first integral are given. 
Guy Casale (LEP)