To provide appropriate information, providing services at a low cost, in which the number of cables for information sending and receiving inside a building can be reduced and the construction cost for cabling is decreased markedly.

In this information-providing method, at lease a part out of the information inside a building 1 is gathered via a communication network, using evanescent communication and charged according to its contents, when charging a customer. With this method, the number of the cables inside the building can be reduced; the cost of construction for the cabling can also be decreased; addition of a facility, a device, and the like, inside the building can be facilitated easy; and the customer can obtain easily required information at low cost, when necessary.