A diamond type cam for rock climbing is provided, which includes a body having an operating member provided thereon, a slide member slidably coupled to the body, a plurality of extension cams each of which has one end that is rotatably coupled to the body and the slide member and an extended end portion that is rotatably hinge-coupled, and a plurality of wires each of which has one end that is coupled to a predetermined position of a lower portion of the extension cam and the other end that is rotatably coupled to a predetermined position of the slide member.