Sub test()
Dim i As Long, j As Long, Valeurs, ValeursPrec, EstEgal As Boolean
For i = Range("IV1").End(xlToLeft).Column To 2 Step -1
Valeurs = Range(Cells(3, i), Cells(23, i)).Value
ValeursPrec = Range(Cells(3, i - 1), Cells(23, i - 1)).Value
EstEgal = True
For j = LBound(Valeurs) To UBound(Valeurs)
If Valeurs(j, 1) <> ValeursPrec(j, 1) Then
EstEgal = False
Exit For
End If
Next j
If EstEgal Then
Cells(1, i).EntireColumn.Delete
End If
Next i
End Sub