There is provided a latent image carrier from which data can be reliably read for a long time. It includes a data storage layer (2) having a latent image pattern formed of fine phosphor paticles dispersed and held on a substrate (4a). When the layer (2) is irradiated with light having a predetermined wavelength, the luminescence from the fine phosphor particles is read as optical information. When irradiated with such light, the surface of the substrate (4a) has a reflectivity of at least 20 %. The data storage layer (2) has a thickness T of 0.5 to 20 νm above the upper surface of the substrate (4a), and a protective sheet (6a) is laminated on the substrate (4a) to cover the data storage layer (2) as a whole.