Abstract: According to one aspect of the present disclosure, there is provided a cleaning method including: cleaning a component in which a deposit adhering to the component constituting an apparatus is removed by supplying and discharging a cleaning gas, wherein the act of cleaning includes controlling the apparatus so that a signal, which indicates a concentration of a predetermined gas generated by a reaction of the deposit and the cleaning gas, reaches a predetermined upper limit value or less and then stays within a range between the predetermined upper limit value and a predetermined lower limit value for a predetermined time period.