This invention provides a safety apparatus for a stapler, the safety apparatus comprises a first plate having a hook and a first opening, wherein when the first plate is in a first position, the hook engages a driving blade for preventing the same from driving out a staple, a second plate substantially parallel to the first plate and having a second opening, a pin having a first and second end, and a first spring urging the pin downward with the first end of the pin protruding from a bottom of a housing body of the stapler and the second end of the pin below the second plate, wherein when the housing body is pressed against an object, the first end of the pin is pushed into the housing body, and the second end of the pin is inserted into both the first and second openings.