To provide a charging method in a public phone system by which a strategic and flexible charge can be adopted in response to the presence of a substitution means in a competition relation and a utility state of a public telephone set or the like.

A public phone system management center stores various charging systems, such as a charging system in response to a charge of a substitute means in the presence of the substitute means in a competing relation at an installed position of a public phone, a charging system in response to speech demands as a result of collecting log information with respect to the use of speech of the public phone, and a charging system in response to an achievement state of a speech result amount with respect to a speech target amount through the measurement of the speech result amount in the case of setting the speech target amount for each public phone, into a charging processing DB 4 via a line control section 13, a connection control section 11, and a charging control section 9, and the charging control section 9 extracts a charging system in response to a state of a public phone at that point of time for each speech and applies the charging system to each speech.