Private Sub ComboBox1_DropButtonClick()
Dim LesVilles As Object, Cel As Range
Set LesVilles = CreateObject("Scripting.Dictionary")
With Sheets("Sheet1")
For Each Cel In .Range("A1:A" & .[A65000].End(xlUp).Row)
If Not LesVilles.Exists(Cel.Value) And Cel.Value <> "" _
Then LesVilles.Add Cel.Value, Cel.Value
Next Cel
End With
Me.ComboBox1.List = Application.Transpose(LesVilles.items)
End Sub