A method for controlling a heat storage device comprising: a heat storage circuit formed by annularly connecting, to each other through a pipe (14, 15), heat storage means in which latent heat storage material (1, 1a, 1b, 1c) and heating medium exchange heat, and heating means for heating the heating medium; and a control device for executing a heat storing operation mode, at least in which the heating medium is heated by the heating means to predetermined heating temperature, and in which heat is transferred to the heat storage means by the heated heating medium, wherein in the heat storing operation mode, the control device determines a heat storage state in which sensible heat exchange is started at least in a portion of the latent heat storage material (1, 1a, 1b, 1c), in the heat storing operation mode using a temperature of the heating medium which flows out from the heat storage means or elapsed time in the heat storing operation mode, and when the heat storage state is determined, the control device lowers heating ability of the heating means, characterized in that the heat storage means includes a plurality of latent heat storage materials (1, 1a, 1b, 1c) having different melting points, the heating medium flows through the heat storage means in the heat storing operation mode such that heat exchange is carried out in the plurality of latent heat storage materials (1, 1a, 1b, 1c) in a melting point-lowering order, in the heat storing operation mode, the control device controls the heating means such that the heating temperature becomes higher than a highest first melting point among the melting points of the latent heat storage materials (1, 1a, 1b, 1c) which are objects of heat storage, and when the heat storage state is determined, the control device lowers heating ability of the heating means such that the heating temperature does not become equal to or lower than the first melting point. a heat storage circuit formed by annularly connecting, to each other through a pipe (14, 15), heat storage means in which latent heat storage material (1, 1a, 1b, 1c) and heating medium exchange heat, and heating means for heating the heating medium; and a control device for executing a heat storing operation mode, at least in which the heating medium is heated by the heating means to predetermined heating temperature, and in which heat is transferred to the heat storage means by the heated heating medium, wherein in the heat storing operation mode, the control device determines a heat storage state in which sensible heat exchange is started at least in a portion of the latent heat storage material (1, 1a, 1b, 1c), in the heat storing operation mode using a temperature of the heating medium which flows out from the heat storage means or elapsed time in the heat storing operation mode, and when the heat storage state is determined, the control device lowers heating ability of the heating means, characterized in that the heat storage means includes a plurality of latent heat storage materials (1, 1a, 1b, 1c) having different melting points, the heating medium flows through the heat storage means in the heat storing operation mode such that heat exchange is carried out in the plurality of latent heat storage materials (1, 1a, 1b, 1c) in a melting point-lowering order, in the heat storing operation mode, the control device controls the heating means such that the heating temperature becomes higher than a highest first melting point among the melting points of the latent heat storage materials (1, 1a, 1b, 1c) which are objects of heat storage, and when the heat storage state is determined, the control device lowers heating ability of the heating means such that the heating temperature does not become equal to or lower than the first melting point.