There are shortcuts for Flash Builder common features but Project-->Clean... isn't one of them. Eclipse has an interesting Keyboard Shortcut in CTRL+3 - Quick Access. The Quick Access shortcut allows you to hit the shortcut then just start typing the name of the feature you want to use - and there is a big list available to you in Eclipse. A bonus to the Quick Access shortcut is that the last feature you used can be used by hitting return. So to set up a shortcut for Project-->Clean there are just a couple steps.