An acceleration sensor and an angular velocity sensor are sealed in respective pressure atmospheres suitable therefor in the process of a series of bonding steps, thereby improving the detection sensibilities of the sensors.A movable member 111 of an acceleration sensor 11 and a vibrator 121 of an angular velocity sensor 12 are fabricated on the same sensor wafer 10 with a wall 16 interposed therebetween. A cap wafer 20 is formed in which gaps 21, 22 corresponding to the movable member 111 of the acceleration sensor 11 and the vibrator 121 of the angular velocity sensor 12 are provided. Bumps 23 are disposed near the gap 22 of the angular velocity sensor 12. The acceleration sensor 11 is sealed at atmospheric pressure. Then, the angular velocity sensor 12 is subjected to high temperature and a high-load and is vacuum-sealed. Thereafter, cutting with a diamond grindstone and mounting of circuit substrates and a wiring substrate are performed to form a combined sensor.