An air shut-off valve apparatus for being connected to a fuel cell stack, comprising: a valve body having an inlet air path configured to be connected to a cathode of the fuel cell stack and for letting air that is to be injected into the fuel cell stack flow through, and an outlet air path for letting air discharged from the fuel cell stack flow through, a bypass body having a bypass air path that connects the inlet air path and the outlet air path ; and characterized in that : the air shut-off valve apparatus further comprises a valve flap disposed at the valve body in a hinged manner and configured to open and close the inlet air path and the outlet air path at a first side thereof, and to open and close the bypass air path at a second side thereof, wherein the valve flap is tilteable and configured to have a first position (A), a second position (B), and a third position (C), such that: the inlet air path and the outlet air path are closed, and the bypass air path is open, when the valve flap is in the first position (A), the inlet air path , the outlet air path , and the bypass air path are open, when the valve flap is in the second position (B), and the inlet air path and the outlet air path are open, and the bypass air path is closed, when the valve flap is in the third position (C). a valve body having an inlet air path configured to be connected to a cathode of the fuel cell stack and for letting air that is to be injected into the fuel cell stack flow through, and an outlet air path for letting air discharged from the fuel cell stack flow through, a bypass body having a bypass air path that connects the inlet air path and the outlet air path ; and characterized in that : the air shut-off valve apparatus further comprises a valve flap disposed at the valve body in a hinged manner and configured to open and close the inlet air path and the outlet air path at a first side thereof, and to open and close the bypass air path at a second side thereof, wherein the valve flap is tilteable and configured to have a first position (A), a second position (B), and a third position (C), such that: the inlet air path and the outlet air path are closed, and the bypass air path is open, when the valve flap is in the first position (A), the inlet air path , the outlet air path , and the bypass air path are open, when the valve flap is in the second position (B), and the inlet air path and the outlet air path are open, and the bypass air path is closed, when the valve flap is in the third position (C). the air shut-off valve apparatus further comprises a valve flap disposed at the valve body in a hinged manner and configured to open and close the inlet air path and the outlet air path at a first side thereof, and to open and close the bypass air path at a second side thereof, wherein the valve flap is tilteable and configured to have a first position (A), a second position (B), and a third position (C), such that: the inlet air path and the outlet air path are closed, and the bypass air path is open, when the valve flap is in the first position (A), the inlet air path , the outlet air path , and the bypass air path are open, when the valve flap is in the second position (B), and the inlet air path and the outlet air path are open, and the bypass air path is closed, when the valve flap is in the third position (C). the inlet air path and the outlet air path are closed, and the bypass air path is open, when the valve flap is in the first position (A), the inlet air path , the outlet air path , and the bypass air path are open, when the valve flap is in the second position (B), and the inlet air path and the outlet air path are open, and the bypass air path is closed, when the valve flap is in the third position (C). <EOS>