An object is to surely hold a stent formed of a biodegradable polymer and shape memorized to an expanded size having a diameter larger than an inner diameter of a vessel on a balloon in contracted state. A stent apparatus comprises a stent formed of a biodegradable polymer material using polylactic acid having a shape memory property as a tubular shape and shape memorized to a size capable of scaffolding a vessel from the inside when implanted in the vessel and a stent holding member formed of a biodegradable polymer material for covering the outer surface of the stent to hold the stent in a contracted state that is smaller in diameter than the shape memorized size, wherein a stent detecting member is attached to the stent and a part of the stent holding member is fixed to the stent detecting member to prevent dislocation between the stent and the stent holding member.
