To provide a cab of construction machinery capable of surely and smoothly performing the unlocking of a door.

This cab of construction machinery is formed by providing the door opening and closing an opening part, installing an opening and closing handle on one end side of the door, installing on the other end side a close locking means locking the door at a closed position, mounting levers 14a and 14b between the opening and closing handle and the close locking means rotatably about a pivot shaft 13, and transmitting the operating force of the opening and closing handle to the close locking means through the levers 14a and 14b so as to perform the unlocking of the door. The line of action of force between the opening and closing handle and the levers 14a and 14b is crossed with the rotating surface of the levers 14a and 14b, and a stopper 19 receiving the component of the force in the direction of a rotating axis is disposed on the side that the force is acting.