HEAT STORAGE DEVICE

PROBLEM TO BE SOLVED: To provide a heat storage device capable of inhibiting degradation of a chemical heat storage material due to an excessive temperature rise.SOLUTION: A heat storage device includes a chemical heat storage material 102 for generating heat by reaction with a reaction medium and regenerating the reaction medium by absorbing heat, and a heat exchanger which makes the chemical heat storage material 102 and a heat exchange medium exchange heat to thus transfer heat from the chemical heat storage material 102 to the heat exchange medium when the chemical heat storage material generates heat, and makes the heat exchange medium transfer heat to the chemical heat storage material 102 when the chemical heat storage material absorbs heat, and in the heat exchanger, a heat transfer distance d1 between the chemical heat storage material 102 and the heat exchange medium and a thickness of a plate 103 functioning as a heat transfer inclusion are set so that a relationship is established in which a heat removal rate Qb when heat is removed from the chemical heat storage material by allowing the chemical heat storage material 102 to transfer heat to the heat exchange medium is larger with respect to a heat generation rate Qa during heat generation of the chemical heat storage material.