To make it possible to uniformize the output characteristics of an air flow rate sensor by incorporating a hot-wire element having the inserting end of a lead wire to a bobbin thinner than the outer diameter, in the sensor.

A platinum wire 1 is wound on the outer periphery of a cylindrical hollow bobbin 5. Lead wires 4 are fixed to be connected to both the ends in the bobbin 5 via an adhesive 3. The wire 1 is covered with a glass coating 2. The method for cutting the wire 4 has the steps of cutting out a notch at the wire 4 in a cross state from the four sides, fixing the one of the wire 4 having the notch, and pulling the other. In this case, the inner diameter of the bobbin 5 is reduced thereby to reduce the glass agent coating area of the gap between the bottom 5 and the wire 4 to about the half of a conventional product. Thereby, the insertion properties of the wire 4 can be improved. The gap between the wire 4 and the bobbin 5 can be reduced. Accordingly, the scoop-out of the coating 2 is eliminated, and it makes it possible to make the output characteristics of the air flow rate of the hot-water element uniform.