To provide a biological information acquisition system capable of surely switching on/off of a power source of a biological information acquisition device.

The biological information acquisition system includes the biological information acquisition device provided with a biological information acquisition part, and a magnetic field generator capable of generating an AC magnetic field. The biological information acquisition device includes: a power source part capable of supplying driving power of the biological information acquisition part; a magnetic field detection part capable of detecting the AC magnetic field in a coil group for magnetic field detection; and a changeover control part for performing control of switching a switch part connected between the power source part and the biological information acquisition part. The magnetic field generator is provided with a magnetic field generation part capable of generating the AC magnetic field in the coil group for magnetic field generation. The position of the biological information acquisition device is determined such that the AC magnetic field generated from the coil group for the magnetic field generation is interlinked with coil surfaces of respective coils included in the coil group for the magnetic field detection when switching the power source state of the biological information acquisition device.