Error:android-apt-compiler: Cannot run program "sdk_path/build-tools/21.1.2/aapt": java.io.IOException: error=13, Permission denied

I'm using Intellij IDEA 14.1.2, java version "1.6.0_45" and OS Ubuntu 14.04 32bit, Showing this error during execution.

Error:android-apt-compiler: Cannot run program "sdk_path/build-tools/21.1.2/aapt": java.io.IOException: error=13, Permission denied

May I know you how can I solve this error?