Sub Masquer_lignes()
Application.ScreenUpdating = False
Application.Calculation = xlManual
T0 = Timer
For Each cel In Range("A2:A300")
If cel.Value = "" Then
cel.EntireRow.Hidden = True
End If
Next
MsgBox Timer - T0
Application.ScreenUpdating = True
Application.Calculation = xlCalculationAutomatic
End Sub