A hole-forming device includes a pointed shaft which is raisable to a position facing a bottom of a can. The shaft is slidably supported on a support plate, with its lower end projecting downward below the support plate. With the hole-forming device mounted on the bottom of the can, and the bottom of the hole-forming device on a surface, such as a floor, a downward force on the can urges the pointed end of the shaft into the bottom of the can to safely puncture the can.