Patent ID: 8720268

Claim:
A flow rate detection device, comprising: a sensor element; and a support, wherein the sensor element comprises: a cavity which is formed in a rear surface of a plate-shaped semiconductor silicon substrate by removing part of the plate-shaped semiconductor silicon substrate; and a thin film portion which is disposed over the cavity and includes a detecting element, wherein the support comprises a fitting portion into which the sensor element is to be disposed, wherein the sensor element is supported to the fitting portion by an adhesive in a floating manner, wherein an anti-undercurrent material is disposed in a gap formed between the sensor element and the fitting portion, in which the anti-undercurrent material is filled into the gap to the same height as a front surface of the support, and wherein the sensor element has a texture including protrusions and depressions formed on a surface opposed to the fitting portion, and the anti-undercurrent material is brought into contact with the texture.