A volume phase type hologram has a diffraction lattice recorded in a poly(N-vinyl carbazole) polymer layer where the diffraction lattice is recorded throughout the thickness direction of the polymer layer. A method for preparing the volume phase type hologram has the steps of exposing a photosensitive polymer layer provided on a substrate to an interference pattern; subjecting the polymer layer having been exposed to a first development treatment with a first organic solvent; and peeling the polymer layer off the substrate and subjecting the polymer to a second development treatment with a second organic solvent preferentially from the face that had been in contact with the substrate.