在Ajax请求中

I´m trying to load a json-file on my localhost. The file looks like:

{
 "0": {
  "file": {
    "This is something - else": "abz"
  }
 }
}

So when I load this file the - will replaced to � (saw in Firefox Debugger). The interesting thing is, that I have a lot of more items (0-11) and the error appears only on this element.

Can somebody explain me what am I doing wrong? I have specified in the ajax request explicitly utf8