A staple driving system for driving insulated staples to secure an object to a base which includes staples having a generally U-shape including parallel legs with free end portions. A molded body formed of insulating material is located on the free end portions of each staple and is slidable with respect thereto when the staple is driven. The molded body has a generally semi-circular recess formed therein between the legs of the staple for surrounding and engaging a cable, wire, or the like. The molded insulating body of one staple is connected by frangible connections to an adjacent molded body of an adjacent staple so that the staples can be shipped and used in a strip. A staple gun having a magazine formed to receive and guide the insulated staples is also provided along with a pusher shaped to cooperate with guide ribs on the magazine while engaging the molded body and the bight of the last staple of a strip in the magazine to accurately guide the staples in the magazine during operation of the system.