Sub Sample1() Dim i As Long, tmp As String For i = 1 To Workbooks.Count tmp = tmp & Workbooks(i).Name & vbCrLf Next i MsgBox "現在開いているブックは、" & vbCrLf & tmp & "です" End Sub
もしくは
Sub Sample2() Dim wb As Workbook, tmp As String For Each wb In Workbooks tmp = tmp & wb.Name & vbCrLf Next wb MsgBox "現在開いているブックは、" & vbCrLf & tmp & "です" End Sub