A measuring system comprising a light source configured to irradiate light, an acoustic wave receiver configured to receive acoustic waves which are generated by irradiating the light to a specimen, and convert the received acoustic waves to electrical signals, and an image forming apparatus configured to produce image data by using the electrical signals, wherein the acoustic wave receiver is configured to receive a direct wave in the acoustic waves generated from a detection target inside the specimen, which directly reach the acoustic wave receiver, and a reflected wave in the acoustic waves generated from the detection target, which has been reflected by an acoustic wave reflecting surface disposed on the specimen, the image forming apparatus comprising: a data producing unit configured to convert the electrical signal converted from the direct wave and the electrical signal converted from the reflected wave to voxel data or pixel data, thereby producing image data; characterized in that the acoustic wave reflecting surface is disposed on the side of the specimen opposite to the acoustic wave receiver, a determining unit configured to determine whether a position of the voxel data or the pixel data converted from the direct wave and a position of the voxel data or the pixel data converted from the reflected wave are symmetrical with respect to a position corresponding to the acoustic wave reflecting surface on the image data; a tag attaching unit configured to attach tags to the voxel data or the pixel data which are not symmetrical and which are therefore specified as artifacts; and a processing unit configured to execute processing to reduce an image of the voxel data or the pixel data, which are determined to be not symmetrical by the determining unit and further specified as artifacts by the tag attaching unit. wherein the acoustic wave receiver is configured to receive a direct wave in the acoustic waves generated from a detection target inside the specimen, which directly reach the acoustic wave receiver, and a reflected wave in the acoustic waves generated from the detection target, which has been reflected by an acoustic wave reflecting surface disposed on the specimen, the image forming apparatus comprising: a data producing unit configured to convert the electrical signal converted from the direct wave and the electrical signal converted from the reflected wave to voxel data or pixel data, thereby producing image data; characterized in that the acoustic wave reflecting surface is disposed on the side of the specimen opposite to the acoustic wave receiver, a determining unit configured to determine whether a position of the voxel data or the pixel data converted from the direct wave and a position of the voxel data or the pixel data converted from the reflected wave are symmetrical with respect to a position corresponding to the acoustic wave reflecting surface on the image data; a tag attaching unit configured to attach tags to the voxel data or the pixel data which are not symmetrical and which are therefore specified as artifacts; and a processing unit configured to execute processing to reduce an image of the voxel data or the pixel data, which are determined to be not symmetrical by the determining unit and further specified as artifacts by the tag attaching unit. a data producing unit configured to convert the electrical signal converted from the direct wave and the electrical signal converted from the reflected wave to voxel data or pixel data, thereby producing image data; characterized in that the acoustic wave reflecting surface is disposed on the side of the specimen opposite to the acoustic wave receiver, a determining unit configured to determine whether a position of the voxel data or the pixel data converted from the direct wave and a position of the voxel data or the pixel data converted from the reflected wave are symmetrical with respect to a position corresponding to the acoustic wave reflecting surface on the image data; a tag attaching unit configured to attach tags to the voxel data or the pixel data which are not symmetrical and which are therefore specified as artifacts; and a processing unit configured to execute processing to reduce an image of the voxel data or the pixel data, which are determined to be not symmetrical by the determining unit and further specified as artifacts by the tag attaching unit.