A hand operated stapling tool, which uses the energy stored in a spring to install staples by an impact blow, is disclosed. A housing body is preferably cast or molded. A handle is pivotally attached to the rear end of the housing body, pressing down the handle stores energy in a power spring by bending the middle section of the power spring, and further pressing down the handle unlocks the front end of the power spring which forces a driving blade to move downward and expels a staple out of the bottom of the housing body. A staple feeding track is formed at the bottom of the housing body, and the stored staples are secured by a rear-hinged panel.