1. A stereoscopic display method comprising: a feature portion detecting step of detecting a feature portion in a display target specified by 3-dimensional information; a sampling point setting step of setting sampling points at a high density into the feature portion detected by said feature portion detecting step and for setting sampling points at a low density into a non-feature portion as a portion other than said feature portion; a phase calculating step of calculating a hologram phase distribution with respect to the sampling points set in said sampling point setting step; a phase distribution expressing step of expressing the phase distribution calculated by said phase calculating step; and a wave front converting step of converting the phase distribution expressed by said phase distribution expressing step into a wave front of the light and for displaying a solid image.