What is the equivalent release function for CoCreateInstance?

I know that the Windows API function CoCreateInstance lets you create an instance of a specified class with a specified interface that's implemented by that class (based on the inteface GUID and class GUID you provide). However, how do you delete this instance? Is there a Windows API function that likewise lets you delete an instance? I know that for kernel32 objects you have CloseHandle, and for GDI objects you have DeleteObject and ReleaseObject. I'm not sure what the API function is to delete a COM object though.