Sub essai()
Set f1 = Sheets("feuil1")
Set f2 = Sheets("feuil2")
ligneBD = 2
finBD = f1.[C65000].End(xlUp).Row
LigneResult = 2
Do While ligneBD <= finBD
marque = f1.Cells(ligneBD, 2)
Do While (f1.Cells(ligneBD, 2) = marque Or f1.Cells(ligneBD, 1) = "") And ligneBD <= finBD
ref = f1.Cells(ligneBD, 3)
f2.Cells(LigneResult, 2) = f1.Cells(ligneBD, 2)
numeros = f1.Cells(ligneBD, 4)
a = Split(numeros, "/")
For i = LBound(a) To UBound(a)
f2.Cells(LigneResult, 3) = ref
f2.Cells(LigneResult, 4) = Trim(a(i))
LigneResult = LigneResult + 1
Next i
ligneBD = ligneBD + 1
Loop
Loop
End Sub