PURPOSE: To allow a handling method to be easily mastered in a shorter time by temporarily switching a display to an image displaying mode at the input of a video signal which a playback means outputs, and displaying control and maintenance methods on the working device using images and voices.

CONSTITUTION: Instructions about the control and maintenance methods of a parts mounting device are recorded on a video cassette tape as image and voice information and are edited with itemized indexes to produce an 'operating instructions video'. To make an operator master the control and maintenance methods of the parts mounting device 1, the operating instructions video are loaded into a VCR 2 and its reproduced image is displayed on the CRT display screen 130 of a monitor display 13 and its reproduced voice is emitted from a speaker 3. The operator holding a remote controller 4 plays back the operating instructions video while skipping to the start of each instruction item to master the operating procedures through visual and auditory recognition.