the incident angle of the reference light is changed by the mirror 31 then the information of the data page to be recorded next is multiplexed on the same recording area as interference information in the same manner after that when only the same reference light 12 b as the one in recording is irradiated to a recording area of the hologram recording medium 24 as reconstruction reference light 12 b the diffracted light reflecting the interference information recorded on the hologram recording medium 24 occurs and becomes reconstruction light 13 a through the lenses 25 and 26 which are included in a 4f system and is collected by the aperture 27 the part generating the diffracted light and the light collecting part of the aperture 27 are related as an object and a mirror image the light excluding zeroth order light and or light due to crosstalk from an adjacent recording area are removed by the aperture 27 and the light having reconstruction information only passes therethrough and is further collected by the lens 28 to the imaging device 29 and is photoelectrically transduced by the imaging device 29 to reconstruction data here as shown in fig2 the aperture 27 has a light shield having a hole 27 a the size of the hole 27 a is generally defined to a threshold amount of aperture for this reason the reconstruction light 13 a generated from a target recording area passes through the hole 27 a and unnecessary.