Provided is a waveform processing assistance system for helping users determine the value of a parameter which is necessary in a waveform processing method for determining the rising and falling points of a peak and whose validity cannot be easily and intuitively determined The system includes: a waveform displayer for showing, on a display screen, a waveform including a peak; a marker displayer for showing, on the display screen, a marker which is capable of being moved by a user; and a slope information displayer for showing information related to the slope of the waveform at a point lying on the waveform and meeting the marker, or at a point which lies on the waveform, which meets the marker, and at which a predetermined operation has been performed by the user. Examples of the slope-related information include a numerical value of the slope, a tangent, and a grid.