To propose a method for setting a gas rate which is valid for promoting photovoltaic power generation and gas in a general housing equipped with a photovoltaic power generation device.

In a method for setting a gas rate in a gas consumption place to which power is supplied by photovoltaic power generation, a gas rate in the power generation period of a photovoltaic power generation device 6 (ST1) and a preliminarily set power generation validating time zone 24S (ST2) is calculated by using a discount gas volume-controlled unit price b1 (ST4, ST5), and otherwise, the gas rate is calculated by using a basic gas volume-controlled unit price bo (ST3, ST5). Thus, it is possible to vary a gas rate menu, and to promote the combined use of photovoltaic power generation and gas.