Book excerpt: This Element is a survey of central topics in the metaphysics of material objects. The topics are grouped into four problem spaces. The first concerns how an object's parts are related to the object's existence and to the object's nature, or essence. The second concerns how an object persists through time, how an object is located in spacetime, and how an object changes. The third concerns paradoxes about objects, including paradoxes of coincidence, paradoxes of fission, and the problem of the many. The fourth concerns views with radical consequences regarding the existence of composite material objects, including mereological nihilism, ontological anti-realism, and deflationism.