An abnormality estimation apparatus for estimating an abnormality in a belt of a belt conveyor includes a displacement part that is displaced in accordance with tension or a change of the tension of the belt when the displacement part is caused to abut against the belt to receive the tension of the belt, an elastic body that is elastically deformed in accordance with displacement of the displacement part, a heat flow sensor that detects a heat flow occurring due to elastic deformation of the elastic body, and an abnormality estimation part that estimates whether there is an abnormality in the belt based on a detection result by the heat flow sensor.