Abstract: A battery container is provided with a battery cover having side walls so that a gap is formed between the side walls of the container and the side walls of the cover. The upper end portion of a bottomed heat-shielding case is inserted into this gap so that the heat-shielding case is detachably attached to the battery container and covers the container and forms a space between the container and the case. The space between the container and case is closed to air outside the case and air convection between the outside air and the air inside the space can be prevented thereby increasing the heat-shielding effect for protecting the storage battery from high temperatures. Additionally, the heat-shielding case is designed to be attached securely to the battery container (1) to make one body therewith, making it easier to mount and dismount them in an automobile engine compartment.