An image recording device comprising: an image acquisition unit (110, 134) that acquires a plurality of images; a group determination unit that determines a group of each image acquired by the image acquisition unit (110, 134); a file creating unit that connects group-by-group images which are classified by the groups determined by the group determination unit, each of which includes a header section, to create a multi-image file that is a single file containing a plurality of connected images; and a recording unit that records the group-by-group multi-image file created by the file creating unit, wherein the group determination unit comprises a classification information acquisition unit that acquires, for each image acquired by the image acquisition unit, at least one of presence/absence of a face in the image, a type of imaging mode, an imaging location, imaging date/time, and an imaging time zone as classification information, and the group determination unit determines the groups of the acquired images based on the acquired classification information; and wherein the classification information acquisition unit further comprises a classification information setting unit that sets a type of the classification information to be acquired by a selection of a user, and the classification information acquisition unit acquires the classification information set by the classification information setting unit for each image acquired by the image acquisition unit (110, 134), wherein if the image acquisition unit (110, 134) acquires a new image, the group determination unit determines a group corresponding to the acquired new image, and if there is no existing multi-image file corresponding to the determined group, the file creating unit creates a new multi-image file for recording the acquired new image, and wherein if the image acquisition unit (110, 134) acquires a new image, and the group determination unit determines an existing group corresponding to the acquired new image, the file creating unit updates the existing multi-image file corresponding to the determined group to connect the acquired new image to an image of the existing multi-image file by appending the acquired new image to the existing multi-image file. an image acquisition unit (110, 134) that acquires a plurality of images; a group determination unit that determines a group of each image acquired by the image acquisition unit (110, 134); a file creating unit that connects group-by-group images which are classified by the groups determined by the group determination unit, each of which includes a header section, to create a multi-image file that is a single file containing a plurality of connected images; and a recording unit that records the group-by-group multi-image file created by the file creating unit, wherein the group determination unit comprises a classification information acquisition unit that acquires, for each image acquired by the image acquisition unit, at least one of presence/absence of a face in the image, a type of imaging mode, an imaging location, imaging date/time, and an imaging time zone as classification information, and the group determination unit determines the groups of the acquired images based on the acquired classification information; and wherein the classification information acquisition unit further comprises a classification information setting unit that sets a type of the classification information to be acquired by a selection of a user, and the classification information acquisition unit acquires the classification information set by the classification information setting unit for each image acquired by the image acquisition unit (110, 134), wherein if the image acquisition unit (110, 134) acquires a new image, the group determination unit determines a group corresponding to the acquired new image, and if there is no existing multi-image file corresponding to the determined group, the file creating unit creates a new multi-image file for recording the acquired new image, and wherein if the image acquisition unit (110, 134) acquires a new image, and the group determination unit determines an existing group corresponding to the acquired new image, the file creating unit updates the existing multi-image file corresponding to the determined group to connect the acquired new image to an image of the existing multi-image file by appending the acquired new image to the existing multi-image file.