PURPOSE: To make optical reproduction extremely difficult and to enable easy discrimination of authentification by providing a hologram with an auxiliary frequency which emits diffracted light to adjacent regions at the time of making light of a single wavelength incident on a main space frequency.

CONSTITUTION: This hologram is composed of first diffraction gratings l which have the prescribed main space frequency, are arranged to form desired images and are designed for observation and second diffraction gratings 2 which have the auxiliary space frequency having the specified change width with respective to the main space frequency within the range to permit diffraction in the same direction as the diffraction direction of the first diffraction gratings 1, are arranged in a position to discriminate the optical reproduction on the same plane as the plane of the first diffraction gratings 1 and are designed to prevent the optical reproduction. The auxiliary frequency possessed by the second diffraction gratings 2 is set at the frequency at which the diffracted light is emitted up to the adjacent regions when the light of a single wavelength is inputted with respect to the main space frequency possessed by the first diffraction gratings 1 and, therefore, the regions where an overexposure is resulted and the regions where an underexposure is resulted are formable and the optical reproduction is made difficult.