To provide a sensor module which can be driven with less energy while keeping its performance.

An operational processor 13 obtains a change in an acceleration detected by an acceleration sensor 12, and a judging device 14 compares the magnitude of the change in the acceleration with data stored in a memory 15. As a result, if the change in the acceleration is judged to be large, a power supply 15 is controlled so as to shorten a sampling period of a magnetic sensor 11. In addition, if the change in the acceleration is judged to be small, the power supply 15 is controlled so as to lengthen the sampling period of the magnetic sensor 11.