A multichip sensor includes an element chip having a detection element of a sensor; a signal-processing IC chip having a signal-processing IC for processing an output signal of the detection element; and a package adapted to accommodate at least the element chip and the signal-processing IC chip and having a surface to be mounted on an ECU board. The plane of the element chip and the surface to be mounted on the ECU board are perpendicular to each other. The plane of the signal-processing IC chip, which is greater than the element chip, and the surface to be mounted on the ECU board are in parallel with each other.