An information processing device (100, 100a, 100b, 200), the information processing device being a client device and comprising: an image acquisition unit that acquires a captured image of a real space (11a, 11b) from an image capture device; a communication unit that communicates with a server device; a setting unit that sets, in association with the real space (11a, 11b), an augmented reality space that virtually augments the real space (11a, 11b) depicted in the captured image by discretizing, in units of voxels, real objects within a real space depicted in the captured image, wherein the augmented reality space is shared among multiple users, the augmented reality spaces of multiple users differing according to related information that relates to the captured image, wherein the related information includes an attribute of a reference object (Rlla, R11b, R19, R19c, R19d, R19e, R21, R21a, R21b, R21c, R21d, R21e) depicted in the captured image, wherein the reference object is a real marker object and wherein the augmented reality coordinate system is set with reference to the position and orientation of the reference object; and a control unit (118, 146) that causes an image of a virtual object (All, A12, A13, V10, V10a, V11a, V12, V13, V16) placed for each user (Ua, Ub, Uc, Ud, Ue) within the augmented reality space set by the server device to be displayed on a screen, wherein an augmented reality space is set by merging multiple user-specific augmented reality spaces which are respectively constructed on the basis of captured images from these multiple users, wherein the setting unit merges the multiple, user-specific augmented reality spaces using logical operations in units of voxels after aligning the multiple, user-specific augmented reality spaces by taking the position and orientation of the reference object as a reference. an image acquisition unit that acquires a captured image of a real space (11a, 11b) from an image capture device; a communication unit that communicates with a server device; a setting unit that sets, in association with the real space (11a, 11b), an augmented reality space that virtually augments the real space (11a, 11b) depicted in the captured image by discretizing, in units of voxels, real objects within a real space depicted in the captured image, wherein the augmented reality space is shared among multiple users, the augmented reality spaces of multiple users differing according to related information that relates to the captured image, wherein the related information includes an attribute of a reference object (Rlla, R11b, R19, R19c, R19d, R19e, R21, R21a, R21b, R21c, R21d, R21e) depicted in the captured image, wherein the reference object is a real marker object and wherein the augmented reality coordinate system is set with reference to the position and orientation of the reference object; and a control unit (118, 146) that causes an image of a virtual object (All, A12, A13, V10, V10a, V11a, V12, V13, V16) placed for each user (Ua, Ub, Uc, Ud, Ue) within the augmented reality space set by the server device to be displayed on a screen, wherein an augmented reality space is set by merging multiple user-specific augmented reality spaces which are respectively constructed on the basis of captured images from these multiple users, wherein the setting unit merges the multiple, user-specific augmented reality spaces using logical operations in units of voxels after aligning the multiple, user-specific augmented reality spaces by taking the position and orientation of the reference object as a reference.