mechanism 13 moves the vibrometer 12 the camera 21 moves therewith the camera 21 is mounted so that the lens thereof face in the same direction as the detecting face of the vibrometer 12 the control board 16 is further provided with a monitoring tv set 22 for monitoring an image signal c 39 from the tv camera transmitted from the communication apparatus 14a to the apparatus 14b this enables the operator 17 looking at the tv set 22 to recognize at a glance the vibration of the object 15 to be monitored since the tv camera always faces at the same direction as the vibrometer 12 thereby advantageously resulting in a more convenient and manageable operation it is to be noted that in the above embodiment the tv camera 21 is mounted on the same angle adjusting mechanism 13 as the non contacting vibrometer 12 however an additional angle adjusting mechanism may be provided so that both mechanisms are independently controlled to face the same direction it is also to be noted that the above embodiments have been described assuming a man operates the system however an automatic diagnosis system may be realized by preliminarily determining locations of objects to be monitored storing data representative of the determined locations and data representative of standard vibration values automatically controlling the travelling unit to run along a predetermined route according to the stored location data measuring the vibration of the objects at the predetermined places and comparing the actual vibration values with the stored standard values to determine whether or not any malfunctions exist further although a travelling mechanism of a rail use type has been described a travelling mechanism as a movable means running on the floor of a plant along an.