The image display method comprises a three-dimensional image creating step that creates a three-dimensional image based on volume data; a cutting plane setting step that sets a cutting plane that cuts the three-dimensional image at an arbitrary position; and a positional relationship display image creating step that creates a positional relationship display image representing the mutual positional relationship between the three-dimensional image and the cutting plane, in which the opacity of the cutting plane in the positional relationship display image is adjusted so that a portion of the three-dimensional image that is hidden by the cutting plane is visually recognizable through the cutting plane in the positional relationship display image.