Sub test()
Dim ws As Worksheet, x As Range
If MsgBox("Confirmation de la suppression du matériau", vbYesNo, "Suppression") = vbYes Then
For Each ws In Worksheets
If ws.Name <> "BD_matières" Then
Set x = ws.Range("A:A").Find([num_ligne_A].Value, , xlValues, xlWhole, , , False)
If Not x Is Nothing Then ws.Rows(x.Row).Delete xlUp
End If
Next ws
End If
End Sub