To provide a lightweight and easily attachable/detachable heater jacket improving heating efficiency and saving energy and a container device including the same. Provided is a heater jacket (10) that is attachable to and detachable from an inner surface of a container (12) and has a heating and warming function for heating and keeping a conveying subject inside the container (12) warm, the heater jacket including: a lightweight and flexible heat insulating mat (18a) that includes at least one planar portion (16) with a heater (14) of which a temperature is controlled and which is embedded therein and formed by connecting the respective planar portions (16) in a bendable manner.
