A staple cartridge (A) has a cartridge body (1) and a refill (2) in which connected staples (a) are received. The refill (2) is replaceably attached to the cartridge body (1). A guide section (7) for guiding the connected staples in the refill (2) to a staple drive-out section (6) is provided between a refill installation section (5) and the drive-out section (6). Below the guide section (7) and the refill installation section (5) are arranged a first actuator (11) and a second actuator (12), respectively. The first actuator (11) is actuated depending on whether or not the connected staples (a) in the guide section (7) are present, and the second actuator (12) is actuated depending on whether or not the connected staples (a) in the refill installation section (5) are present. The first actuator (11) and the second actuator (12) move in conjunction with each other.