To provide a flow sensor type flowmeter that is capable of performing calibration without increasing the number of flow rate calibration points and can accurately measure the flow rate.

The flow sensor type flowmeter has a difference detection means 33 for detecting the difference between upstream/downstream temperature sensors, an addition means 35 for detecting the sum of left and right temperature sensors, a division means 41 for dividing the differential output by addition output, a flow rate calculation means 42 for converting the division value to the flow rate value by referring to a flow rate conversion data table 43, a first output correction/ standardization means 44 for correcting and standardizing the difference output by the first offset value when the flow rate is zero and the first span value based on the zero flow rate and the maximum flow rate, and supplying the output after correction/standardization to the division means 41, and the second output correction/ standardization means 45 for correcting/standardizing the addition output by the second offset value when the flow rate is zero and the second span value based on the zero flow rate and the maximum flow rate, and supplying the output after correction/ standardization to the division means 41.