A cloth supply device used for a cloth spreading apparatus that spreads in a left-right direction an upper edge part of a cloth between adjacent corners by respectively grasping these corners of the cloth with a pair of spreading clamps and ejects rearward the cloth of which the upper edge part has been spread, the cloth supply device being configured to convey fed cloths one by one and transfer the adjacent corners of the cloth to the pair of spreading clamps, characterized in that the cloth supply device comprises: double measurement paths extending parallel to each other at a predetermined interval through which a pair of conveying clamps that are respectively fed with the adjacent corners of the upper edge part of the cloth and grasp these corners respectively pass side by side; a sag sensor that measures a degree of sagging of the upper edge part of the cloth between the corners having been respectively grasped by the pair of conveying clamps passing through the double measurement paths side by side; multiple sag-specific supply paths (15, 16) that are specified according to the degree of sagging of the upper edge part and each branch off from the double measurement paths; and cloth classification and supply control means that passes the pair of conveying clamps grasping the corners of the cloth respectively through double sag-specific supply paths corresponding to the degree of sagging of the upper edge part of that cloth among the multiple sag-specific supply paths (15, 16), and transfers the corners of the cloth from the pair of conveying clamps to the pair of spreading clamps that are positioned so as to correspond to the double sag-specific supply paths through which the pair of conveying clamps have been passed among the multiple sag-specific supply paths (15, 16), wherein the sag-specific supply paths (15, 16) into which each of the double measurement paths branches are two paths of an outer supply path and an inner supply path. double measurement paths extending parallel to each other at a predetermined interval through which a pair of conveying clamps that are respectively fed with the adjacent corners of the upper edge part of the cloth and grasp these corners respectively pass side by side; a sag sensor that measures a degree of sagging of the upper edge part of the cloth between the corners having been respectively grasped by the pair of conveying clamps passing through the double measurement paths side by side; multiple sag-specific supply paths (15, 16) that are specified according to the degree of sagging of the upper edge part and each branch off from the double measurement paths; and cloth classification and supply control means that passes the pair of conveying clamps grasping the corners of the cloth respectively through double sag-specific supply paths corresponding to the degree of sagging of the upper edge part of that cloth among the multiple sag-specific supply paths (15, 16), and transfers the corners of the cloth from the pair of conveying clamps to the pair of spreading clamps that are positioned so as to correspond to the double sag-specific supply paths through which the pair of conveying clamps have been passed among the multiple sag-specific supply paths (15, 16), wherein the sag-specific supply paths (15, 16) into which each of the double measurement paths branches are two paths of an outer supply path and an inner supply path.