An opening and closing type shelf fixing clamp comprising: a main body fastened to wires forming both side edges of a shelf and to which a post is fastened; a fixing cover fastened to one side of the main body through a hinge to surround and fix a front surface of the post ; and a fixing lever fastened to an opposite side of the main body through a hinge to press the fixing cover toward the main body so as to stably fix the shelf to the post wherein the fixing cover , which is fastened to the one side of the main body through the hinge to surround and fix the front side of the post , includes: a body formed therein with a post insertion portion having a semi-circular shape to fasten the post; a fastening block formed at one side of the body, inserted into an insertion portion formed at a center of the fixing block of the main body , and rotatably fastened to the main body through the hinge; a tight-contact groove formed at an opposite side of the body, and pulled toward the main body by the fixing lever after a tight-contact protrusion formed in the fixing lever is inserted into the tight-contact groove , thereby stably fixing the post; a first double locking protrusion formed at one side of the tight-contact groove, fastened to a second double locking protrusion formed on the fixing lever , and pulled toward the main body by the fixing lever to stably fix the post; and a pad fastened to the post insertion portion to prevent the shelf from descending on the post. a main body fastened to wires forming both side edges of a shelf and to which a post is fastened; a fixing cover fastened to one side of the main body through a hinge to surround and fix a front surface of the post ; and a fixing lever fastened to an opposite side of the main body through a hinge to press the fixing cover toward the main body so as to stably fix the shelf to the post wherein the fixing cover , which is fastened to the one side of the main body through the hinge to surround and fix the front side of the post , includes: a body formed therein with a post insertion portion having a semi-circular shape to fasten the post; a fastening block formed at one side of the body, inserted into an insertion portion formed at a center of the fixing block of the main body , and rotatably fastened to the main body through the hinge; a tight-contact groove formed at an opposite side of the body, and pulled toward the main body by the fixing lever after a tight-contact protrusion formed in the fixing lever is inserted into the tight-contact groove , thereby stably fixing the post; a first double locking protrusion formed at one side of the tight-contact groove, fastened to a second double locking protrusion formed on the fixing lever , and pulled toward the main body by the fixing lever to stably fix the post; and a pad fastened to the post insertion portion to prevent the shelf from descending on the post. a body formed therein with a post insertion portion having a semi-circular shape to fasten the post; a fastening block formed at one side of the body, inserted into an insertion portion formed at a center of the fixing block of the main body , and rotatably fastened to the main body through the hinge; a tight-contact groove formed at an opposite side of the body, and pulled toward the main body by the fixing lever after a tight-contact protrusion formed in the fixing lever is inserted into the tight-contact groove , thereby stably fixing the post; a first double locking protrusion formed at one side of the tight-contact groove, fastened to a second double locking protrusion formed on the fixing lever , and pulled toward the main body by the fixing lever to stably fix the post; and a pad fastened to the post insertion portion to prevent the shelf from descending on the post. <EOS>