PURPOSE: To easily measure the sensitivity of a semiconductor acceleration sensor and, to easily adjust the sensor by providing a through hole in a sensor chip section facing the weight section of the sensor so that a load can be directly applied to the weight section.

CONSTITUTION: An upper and lower supporting bases 2 and 3 respectively having recesses 6 and 7 are put on the upper and lower surfaces of a sensor substrate 1 provided with a weight section 9 and flexible section 8. Then at least one or more through holes 5 are formed through the upper supporting base 2 at positions facing the weight section 9. Therefore, the output voltage of the sensor can be obtained by directly applying a load of a loading body to the section 9 through the hole 5.