In a thermal-type airflow meter that measures an intake airflow rate in an
internal combustion engine of an automobile or the like, there has been a
problem that pulsation errors caused by external fluctuations under the
environment including a large pulsation and reverse flow in the intake
valve are difficult to be reduced. In order to solve this problem, the
invention provides a flowmeter comprising a detection element that
outputs a non-linear signal corresponding to a flow rate, and a
regulation means that regulates an output signal of the detection element
for controlling. With this construction, the regulation means executes
output regulation processing that regulates irregularities of the
detection element in the output signal, and inequality linearization
processing that regulates an average value of the output signal after the
output regulation processing by means of regulating parameters.