A battery monitoring apparatus, comprising: an electric current information acquirer acquiring information about electric current flowing out of a battery or flowing into the battery; a generated heat amount calculator calculating the amount of heat generated inside the battery, on the basis of the information about electric current acquired by the electric current information acquirer; a temperature information acquirer acquiring temperature information about at least one out of the surface of the battery and a substance in the vicinity of the battery; a discharged heat amount calculator calculating the amount of heat discharged from the surface of the battery, on the basis of the temperature information acquired by the temperature information acquirer; and an internal temperature calculator calculating the internal temperature of the battery, on the basis of the generated heat amount information and the information about the amount of heat discharged from the surface of the battery, wherein: the battery is located inside a container having an air inlet and an air outlet; the temperature information acquirer acquires temperature information about air supplied from the air inlet, temperature information about air flowed out from the air outlet and an external surface temperature of the container; and the discharged heat amount calculator acquires information about the amount of air supplied from the air inlet or flowed out from the air outlet, calculates the amount of heat discharged from the container on the basis of information about the amount of air, the temperature information about air supplied from the air inlet, the temperature information about air flowed out from the air outlet and the external surface temperature of the container, and calculates the amount of heat discharged from the surface of the battery on the basis of the information about the amount of heat discharged from the container. an electric current information acquirer acquiring information about electric current flowing out of a battery or flowing into the battery; a generated heat amount calculator calculating the amount of heat generated inside the battery, on the basis of the information about electric current acquired by the electric current information acquirer; a temperature information acquirer acquiring temperature information about at least one out of the surface of the battery and a substance in the vicinity of the battery; a discharged heat amount calculator calculating the amount of heat discharged from the surface of the battery, on the basis of the temperature information acquired by the temperature information acquirer; and an internal temperature calculator calculating the internal temperature of the battery, on the basis of the generated heat amount information and the information about the amount of heat discharged from the surface of the battery, wherein: the battery is located inside a container having an air inlet and an air outlet; the temperature information acquirer acquires temperature information about air supplied from the air inlet, temperature information about air flowed out from the air outlet and an external surface temperature of the container; and the discharged heat amount calculator acquires information about the amount of air supplied from the air inlet or flowed out from the air outlet, calculates the amount of heat discharged from the container on the basis of information about the amount of air, the temperature information about air supplied from the air inlet, the temperature information about air flowed out from the air outlet and the external surface temperature of the container, and calculates the amount of heat discharged from the surface of the battery on the basis of the information about the amount of heat discharged from the container. the battery is located inside a container having an air inlet and an air outlet; the temperature information acquirer acquires temperature information about air supplied from the air inlet, temperature information about air flowed out from the air outlet and an external surface temperature of the container; and the discharged heat amount calculator acquires information about the amount of air supplied from the air inlet or flowed out from the air outlet, calculates the amount of heat discharged from the container on the basis of information about the amount of air, the temperature information about air supplied from the air inlet, the temperature information about air flowed out from the air outlet and the external surface temperature of the container, and calculates the amount of heat discharged from the surface of the battery on the basis of the information about the amount of heat discharged from the container.