A coordinates input device connected to an image processing system such as a copying machine for reading an image recorded on a recording medium and for editing this image. This device includes: a transparent vibration propagating plate to designate an editing area for trimming or masking in contact relation with the recording medium from which the image was read by the image processing system; a vibration pen to input a supersonic vibration by coming into contact with the vibration propagating plate; vibration sensors which are attached to the plate and detect the vibration generated from the vibration pen; and a controller for supplying to the image processing system the editing area information for the recording medium designated by the coordinates of the vibration pen on the plate which were detected by the vibration sensors. The propagation times of the supersonic vibration which is propagated by the vibration propagating plate to the vibration sensors are measured and the coordinates of the position of the vibration pen are calculated on the basis of the measured vibration propagation times. With this apparatus, a desired editing area on an original image can be easily designated through the transparent input tablet and the editing information can be easily controlled.