Provided are techniques for interrupt processing. An interface on the stationary structure is connected to the first interface when the portable structure is held by the stationary structure and is disconnected from the first interface when the portable supporting structure is removed from the stationary structure. In accordance with the present invention, it is possible to produce lithium-silicate-based materials, which are useful as a positive-electrode active material for lithium-ion secondary battery, and the like, at low temperatures by means of relatively easy means.