Patent ID: 6912899

Claim:
A flow rate sensor comprising: an external structural member having a support member and a detector passage disposed at a tip end portion of said support member, a holder insertion aperture being formed in said support member so as to communicate between a base end exterior portion of said support member and said detector passage; a holder mounted to said external structural member by being inserted into said holder insertion aperture such that an element holding portion disposed near a tip end of said holder projects into said detector passage; a flow rate detecting element for detecting a flow rate of a fluid being measured, said flow rate detecting element being disposed on said element holding portion; and an electronic circuit portion for controlling an excitation current flowing to said flow rate detecting element, said electronic circuit portion being electrically connected to said flow rate detecting element, said flow rate sensor having a plug-in construction in which said external structural member is inserted into a mounting aperture that opens onto a main passage through which said fluid being measured flows so as to be positioned with said detector passage in said main passage to detect said flow rate of said fluid being measured, wherein: an electrical connection portion between said flow rate detecting element and said electronic circuit portion is constructed on a portion of said holder positioned inside said holder insertion aperture, and said holder is supported as a cantilever in said external structural member by fixing a base end portion of said holder to said external structural member.