Patent ID: 8039911

Claim:
An MEMS sensor comprising: a substrate; and a diaphragm provided on the substrate that vibrates due to an action of a physical quantity, wherein the diaphragm integrally has a main portion arranged on the substrate in a floating state and supporting portions extending in a direction along the surface of the substrate from two positions in the peripheral edge of the main portion, a plurality of protruding lower stoppers for preventing the main portion and the substrate from adhering to each other are formed on a surface of the main portion opposed to the substrate, and an angle formed by two straight lines connecting the supporting portions and the center of the main portion with one another respectively is set to satisfy the relation of the following formula (1): ( A 2 /A 1)/( B 2 /B 1)≧1 (1) A 2 : maximum vibrational amplitude of the diaphragm in a case of working a physical quantity of a prescribed value on the diaphragm A 1 : maximum vibrational amplitude of the diaphragm in a case of working the physical quantity of the prescribed value on the diaphragm in a structure obtained by omitting one of the supporting portions from the diaphragm B 2 : maximum stress caused in the diaphragm in the case of working the physical quantity of the prescribed value on the diaphragm B 1 : maximum stress caused in the diaphragm in the case of working the physical quantity of the prescribed value on the diaphragm in the structure obtained by omitting one of the supporting portions from the diaphragm.