A wearable electronic device according to the present disclosure includes a first belt, front surface of the first belt being provided with a displaying unit having a curved display face; a second belt; a hinge that connects a first end of the first belt to a first end of the second belt. A shape of a space formed by the first and second belts is an elliptical shape when the device worn around a subject is viewed from a side. The hinge has higher flexibility than the first and second belts. The device has a first engagement unit provided at a second end and a rear surface of the first belt, and in a region where the elliptical shape has smaller curvature than other regions. The device has a second engagement unit provided at an outer side of the second belt and engaging with the first engagement unit.