Patent ID: 7571641

Claim:
A flow meter comprising, a passage forming body including a passage, a lattice arranged at one of an inlet side and an outlet side of the passage forming body to extend across the passage, and a flow rate measuring module for receiving a gaseous matter to measure a flow rate, a part of which flow rate measuring module extends into the passage through a hole of the passage forming body, wherein the passage forming body and the lattice are monolithic with each other to be made of a resin through an injection molding, the passage forming body includes at least one gate trace through which the resin forming the passage forming body and the lattice passed during the injection molding, an axial distance between the gate trace and an end of the passage forming body adjacent to the one of the inlet side and the outlet side being not less than L/2 when L is an axial length of the passage, and an average thickness of the lattice is not less than 0.3 mm and not more than 0.6 mm.