A living body observation system of the invention includes: a living body information acquiring apparatus which includes a living body information acquiring section for acquiring living body information, a wireless transmission section for wirelessly transmitting the living body information, a power source section for supplying driving power for driving the living body information acquiring section and the wireless transmission section, a magnetic field detecting section for detecting a magnetic field from outside and outputting a detection result as an electric signal, and a power supply control section for controlling a supplying state of the driving power supplied to the living body information acquiring section and the wireless transmission section based on the electric signal a magnetic field generating coil a driving circuit for outputting a drive signal for driving the magnetic field generating coil a switch for switching between on and off of a generation state of a magnetic field and a timer for outputting a stop signal for stopping output of the drive signal when a predetermined period has passed following switching from off to on of the switch.
