The built-in Archive Utility provided by Apple, which forms part of Mac OS X, isn’t great. Thankfully, there’s a freeware replacement called The Unarchiver which you can download. This replacement utility is much more capable, designed to handle more formats, and fits in better with the design of the Finder.
It is very simple to use and install – simply copy it into your Applications folder or where ever you prefer, and then set archive filetypes to open using it. This can either be done the usual way, or by double-clicking the icon to show The Unarchiver’s preferences.
I’ve been using this utility for years and I’ve never had any problems with it, it unarchives files really quickly and supports a lot of different archive formats. This is definitely one of the best Mac freebies you can get.