Where is application .config file?

[stricknyn]

To add, the file must be there. Because I can access it and add to it from my program:

Dim config As Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)
        config.AppSettings.Settings.Add("MyKey", "MyValue")

        'Save the configuration file
        config.Save()

        For i As Integer = 0 To ConfigurationManager.AppSettings.Count - 1
            Console.WriteLine("{0}: {1}", ConfigurationManager.AppSettings.AllKeys(i), ConfigurationManager.AppSettings(i))
        Next
        Console.ReadKey()

But when I go to bin folder it's not there.