PURPOSE: To enable the electronic device to be in the adjustment mode in response to a 1st signal and to enable the electronic device to revise a setting value in response to a 2nd signal by providing a jig which revises an internal setting value of the electronic device having the normal mode and the adjustment mode on the adjustment device.

CONSTITUTION: When the adjustment mode is set, an item and a setting value of a channel 1 are displayed on a monitor display device 40. The revision of the item is implemented by turning a jog part 22 of a jig 20. Items whose setting values are able to be revised are indicated on the display screen in a blinked arrow. When the jog part 22 is turned at a proper angle in a forward direction, the blinked arrow is moved to a larger number item. With a shuttle 23 turned by a prescribed angle, the setting value of the item indicated in the arrow is incremented by one. Since each items and each setting value are displayed superimposingly on a picture of an original 19 picked up by an image pickup device 10, the operator revises the setting value while confirming the displayed picture.