ATP synthase is the complex-V of the electron transport chain found in the inner mitochondrial membrane.
It is a protein that has two major components- F1-ATPase and F0-component.
F1- ATPase has 8 subunits and is a peripheral membrane protein. F0 component is an integral membrane protein and is attached to F1 by means of its gamma subunit.
The purpose of ATP synthase is to synthesize ATP from ADP and inorganic phosphate.