AIRFLOW MEASURING APPARATUS

Provided is an airflow measuring apparatus with good measurement accuracy. An airflow measuring apparatus includes: a sub-passage that takes in a part of a flow of fluid flowing through an intake pipe; a sensor element that is disposed in the sub-passage to measure the flow of fluid; a circuit part that converts the flow of fluid detected by the sensor element into an electric signal; a connector part having a connector that is electrically connected to the circuit part to output a signal externally; and a casing that supports the sensor element and the circuit part, the sensor element being disposed in the intake pipe. The sensor element includes a cavity that is disposed at a semiconductor substrate, and a diaphragm including a thin film part that covers the cavity. The sensor element is mounted at a lead frame. The sensor element and the lead frame have surfaces that are mold-packaged with resin so that a diaphragm part of the sensor element and a part of the lead frame are exposed. At least one hole is disposed at the lead frame for communication between the cavity and exterior of the mold package.