Au top cela fonctionne !
Une autre technique a été trouvé aussi :
Dim F1 As Range
Dim i As Integer
Dim s As Double
Dim Vente As Double
Dim Achat As Double
Dim DernLigne As Long
Application.Calculation = xlCalculationManual
DernLigne = Range("A" & Rows.Count).End(xlUp).Row
Set F1 = Sheets("Feuil1").Range("A1:A" & DernLigne)
montant = 0
s = 0
For i = 1 To F1.Rows.Count
If F1(i, 1) >= Cells(2, 8) And F1(i, 1) <= Cells(2, 9) And F1(i, 2) = "BOIS" And F1(i, 4) = "VENTE" Then
s = F1(i, 3) * F1(i, 5)
Vente = Vente + s
End If
If F1(i, 1) >= Cells(2, 8) And F1(i, 1) <= Cells(2, 9) And F1(i, 2) = "BOIS" And F1(i, 4) = "ACHAT" Then
s = F1(i, 3) * F1(i, 5)
Achat = Achat + s
End If
Next i
Cells(4, 9) = Vente
Cells(5, 9) = Achat
Application.Calculation = xlCalculationAutomatic