A chemical heat storage device comprising: a heat storage material accommodation unit which accommodates a chemical heat storage material which is adapted to generate heat and a reaction product by reversible chemical reaction with a reaction medium; a driving unit which is adapted to drive rotation of the heat storage material accommodation unit; and a heat exchange unit which includes a heat transfer unit which extends in at least one heat storage material accommodation unit, and is thermally communicated with the inside and the outside of the heat storage material accommodation unit, wherein the chemical heat storage material is adapted to be stirred by rotation of the heat storage material accommodation unit, heat exchange is adapted to be performed between heat exchange fluid which is adapted to flow through the heat transfer unit and the chemical heat storage material, and a temperature of the heat exchange fluid which is adapted to flow through the heat transfer unit is adapted to be changed; and wherein the reaction medium is water, and wherein when a height of the heat storage material accommodation unit is set as 100%, a height of the accommodated chemical heat storage material in the heat storage material accommodation unit is 40% to 60%; the chemical heat storage device further comprising a chamber which accommodates the heat storage material accommodation unit in a vacuum state; a hole unit which is formed on the heat storage material accommodation unit, and through which vapor is adapted to pass, at the time of heat generation by a chemical reaction of the chemical heat storage material and the reaction medium, and at the time of heating the reaction product to eliminate the reaction medium from the reaction product and to regenerate the chemical heat storage material; and a water accommodation unit which is communicated with the inside of the chamber, and in which vapor which is adapted to be eliminated from the reaction product is adapted to be condensed and accumulated, at the time of performing heating and regenerating of the reaction product in the heat storage material accommodation unit; and wherein, when increasing a temperature of the heat transfer unit by supplying the vapor to the heat storage material accommodation unit from the water accommodation unit through the hole unit, and generating heat by the reaction of the chemical heat storage material with the vapor as the reaction medium, a temperature of the heat exchange fluid which flows through the heat transfer unit is increased. a heat storage material accommodation unit which accommodates a chemical heat storage material which is adapted to generate heat and a reaction product by reversible chemical reaction with a reaction medium; a driving unit which is adapted to drive rotation of the heat storage material accommodation unit; and a heat exchange unit which includes a heat transfer unit which extends in at least one heat storage material accommodation unit, and is thermally communicated with the inside and the outside of the heat storage material accommodation unit, wherein the chemical heat storage material is adapted to be stirred by rotation of the heat storage material accommodation unit, heat exchange is adapted to be performed between heat exchange fluid which is adapted to flow through the heat transfer unit and the chemical heat storage material, and a temperature of the heat exchange fluid which is adapted to flow through the heat transfer unit is adapted to be changed; and wherein the reaction medium is water, and wherein when a height of the heat storage material accommodation unit is set as 100%, a height of the accommodated chemical heat storage material in the heat storage material accommodation unit is 40% to 60%; the chemical heat storage device further comprising a chamber which accommodates the heat storage material accommodation unit in a vacuum state; a hole unit which is formed on the heat storage material accommodation unit, and through which vapor is adapted to pass, at the time of heat generation by a chemical reaction of the chemical heat storage material and the reaction medium, and at the time of heating the reaction product to eliminate the reaction medium from the reaction product and to regenerate the chemical heat storage material; and a water accommodation unit which is communicated with the inside of the chamber, and in which vapor which is adapted to be eliminated from the reaction product is adapted to be condensed and accumulated, at the time of performing heating and regenerating of the reaction product in the heat storage material accommodation unit; and wherein, when increasing a temperature of the heat transfer unit by supplying the vapor to the heat storage material accommodation unit from the water accommodation unit through the hole unit, and generating heat by the reaction of the chemical heat storage material with the vapor as the reaction medium, a temperature of the heat exchange fluid which flows through the heat transfer unit is increased.