This terminal holding device has: an attachment section for attachment to a vehicle; a holding section that has a surface that contacts a terminal device and that is for removably holding the terminal device in a manner such that the display section of the terminal device is exposed; an acceleration sensor that can detect the acceleration in a direction that faces from the contact surface towards the reverse side of the contact surface; and a supply means that is for supplying a detection signal from the acceleration sensor to the terminal device.
