To provide a heat storage apparatus, capable of supplying superheated steam to a plurality of heat loads, without making the superheated steam branch at the outlet side of a heat storage tank.

Two heat transfer tubes 16, 17 are arranged in a single heat storage tank 12. Water is supplied from a common water source to both the tubes 16 and 17 and is branched to both the tubes 16 and 17 at the inlet side of the tank 12. That is, a branch valve 20 is disposed at the inlet side of the tank 12, and the water from the water source is branched to both the tubes 16 and 17. When first and second solenoid valves 18 and 19 are respectively opened and supplied into both the tubes 16 and 17, this water becomes the superheated steam, which is supplied to the first an second heat loads. Thus, superheated steam can be supplied to the plurality of the heat loads, without branching the superheated steam at the outlet side of the tank 12.