Patent ID: 7707894

Claim:
A mechanical quantity measuring apparatus having a strain detector formed on a single crystal semiconductor substrate for detecting a strain, and bonded to or buried in an object to be measured to measure a strain, wherein: a Wheatstone bridge circuit having a pair of sensor resistor layers and a pair of dummy resistors disposed on a principal surface of said single crystal semiconductor substrate, a resistance of each dummy resistor being equal to a resistance of one of the sensor resistor layers and each sensor resistor layer including a P-type impurity diffusion layer whose longitudinal direction is set to a <110> crystal plane direction of the single crystal silicon semiconductor substrate; and a plurality of second resistor layers not constituting said Wheatstone bridge circuit formed along a longitudinal direction of each of the sensor resistor layers and each of the dummy resistors, wherein said second resistor layers have no electrical connection to each other, wherein, for each sensor resistor layer, a pair of second resistor layers is formed on opposite sides thereof.