PURPOSE: To provide a support device for a GPS antenna by which the antenna is automatically supported horizontally while the antenna is moved on a small sized vehicle.

CONSTITUTION: A support mechanism 11 comprising a 1st turning body 29 turnable around a 1st shaft 27A and a 2nd turning body 33 supported by the 1st turning body 29 turnably around a 2nd shaft 31A orthogonal to the 1st shaft 27A is provided to the support device and a GPS antenna is supported by the 2nd turning body 33. Then actuators 13, 15 to turn the 1st turning body 29 and the 2nd turning body 33 are provided, tilt detection means 41, 43, 45, 47 to detect the tilt of the 1st and 2nd turning bodies 29, 33, and a correction quantity calculation means 19 calculating a turning correction quantity around the 1st and 2nd shafts 27A, 31A of the 1st turning body 29 and the 2nd turning body 33 based on the result of detection of the tilt detection means 41, 43, 45, 47 is provided. Furthermore, a drive means 21 to drive the actuators 13, 15 based on the result of calculation of the correction quantity calculation means 19 is provided to the support device.