Texmaker and TeXstudio ⇒ Backslash on Mac with Japanese keyboard

[lorenz]

Hello everybody,
I am new and I have a problem with texmaker.
Every time I need a ''\'' (often) I must copy and glue it because the shortcut usually working on a japanese mac keyboard (there is no direct button here), option+¥, in texmaker does not work.
As you see it works in (all?) other programs.

Any ints on how I can solve the problem?

Thank you very much!

Lorenzo.