A sensor unit has a reference base. An acceleration sensor block and angular velocity sensor support rods are arranged on the reference base, using a bottom face and one side face of the reference base as reference faces. Three acceleration sensors, which detect accelerations that act in the directions in which an X-axis, a Y-axis, and a Z-axis extend, are fitted to three faces of the acceleration sensor block, respectively. Three angular velocity sensors, which detect angular velocities about the X-axis, the Y-axis, and the Z-axis, are fitted to boards that are fitted, via rubber bushings serving as vibration-proofing rubber members, to the angular velocity sensor support rods with screws, respectively.