Sub recherche()
Dim i As Long, k As Long
Sheets("Feuil1").Activate
With Sheets("Feuil2")
For i = 3 To Cells(Rows.Count, 1).End(xlUp).Row
For k = 3 To .Cells(.Rows.Count, 1).End(xlUp).Row
If Cells(i, 2) = .Cells(k, 2) Then
Cells(i, 3) = "oui"
Exit For
End If
Next k
If k > .Cells(.Rows.Count, 1).End(xlUp).Row Then Cells(i, 3) = "non"
Next i
End With
End Sub