A flow rate detector of an exhalation measurement device includes: a pipe body having a flow inlet at a first end into which exhalation flows, and a flow outlet at a second end out of which exhalation flows； and a differential pressure sensor connected to the pipe body. The pipe body includes: a partition gasket which partitions the inside of the pipe body into a flow-in space of exhalation and a flow-out space of exhalation； a connection aperture being provided at the flow-in space and connecting the differential pressure sensor to the flow-in space； a connection aperture being provided at the flow-out space and connecting the differential pressure sensor to the flow-out space； and an air duct of an elongated shape, extending through the partition gasket and allowing the flow-in space and the flow-out space to communicate with each other.
