Air flow rate measuring device

An air flow rate measuring device adapted to be disposed in an intake passage leading to an engine, for taking in a part of air flowing through the intake passage and generating a heat transfer phenomenon between the device and the air taken in thereby to measure a flow rate of air suctioned into the engine, the device comprising:

• a housing that defines an internal flow passage, through which the air taken in passes, and that includes a contact surface;
• a sensor assembly that includes:
• a sensor chip that is configured to generate an electrical signal through the heat transfer phenomenon, wherein the sensor assembly is inserted and fixed in the housing such that the sensor chip is exposed to the internal flow passage;
• and
• a contact surface that is in surface contact with the contact surface of the housing;
• and
• an urging mechanism that is configured to press the contact surface of the sensor assembly on the contact surface of the housing, so that the sensor assembly is fixed to the housing by the urging mechanism.