A flow rate measurement apparatus having: a flow rate measurement unit for measuring the flow rate of a fluid flowing into a flow path; a flow rate information storage unit for storing the flow rate value measured in said flow rate measurement unit; an appliance registration storage unit for storing the flow rate value for each appliance; and an appliance determination unit for making a comparison between a flow rate pattern of the flow rate value measured in said flow rate measurement unit and a flow rate pattern of an appliance determination value stored in said appliance registration storage unit and determining the use state of an appliance connected to the downstream side of said flow rate measurement unit; and an unknown appliance registration unit, if there is a flow rate pattern according to which said appliance determination unit cannot determine an appliance based on information in said appliance registration storage unit, for registering the information as unknown data; characterized in that: the flow rate measurement apparatus further comrises: a recheck unit for rechecking based on the data in said flow rate information storage unit if registration data exists in said unknown appliance registration unit; wherein if information is registered in the unknown appliance registration unit the recheck unit rechecks which appliance it is by comparing the determination of the portion of the unknown appliance, wherein the margin width for a flow rate change at the starting time and the registration value are widened, based on the data record of the flow rate in the flow rate information record unit. a flow rate measurement unit for measuring the flow rate of a fluid flowing into a flow path; a flow rate information storage unit for storing the flow rate value measured in said flow rate measurement unit; an appliance registration storage unit for storing the flow rate value for each appliance; and an appliance determination unit for making a comparison between a flow rate pattern of the flow rate value measured in said flow rate measurement unit and a flow rate pattern of an appliance determination value stored in said appliance registration storage unit and determining the use state of an appliance connected to the downstream side of said flow rate measurement unit; and an unknown appliance registration unit, if there is a flow rate pattern according to which said appliance determination unit cannot determine an appliance based on information in said appliance registration storage unit, for registering the information as unknown data; the flow rate measurement apparatus further comrises: a recheck unit for rechecking based on the data in said flow rate information storage unit if registration data exists in said unknown appliance registration unit; wherein if information is registered in the unknown appliance registration unit the recheck unit rechecks which appliance it is by comparing the determination of the portion of the unknown appliance, wherein the margin width for a flow rate change at the starting time and the registration value are widened, based on the data record of the flow rate in the flow rate information record unit. a recheck unit for rechecking based on the data in said flow rate information storage unit if registration data exists in said unknown appliance registration unit; wherein if information is registered in the unknown appliance registration unit the recheck unit rechecks which appliance it is by comparing the determination of the portion of the unknown appliance, wherein the margin width for a flow rate change at the starting time and the registration value are widened, based on the data record of the flow rate in the flow rate information record unit.