Sub Efface_Tout()
Dim Ws As Worksheet, x&
Application.ScreenUpdating = False
For Each Ws In ThisWorkbook.Sheets
With Ws
x = .Range("a" & Rows.Count).End(xlUp).Row
.Range("a" & x).End(xlUp).CurrentRegion.Offset(1).ClearContents
End With
Next Ws
End Sub