To provide a clinker cooling device capable of preventing clinker and/or cooling air from backflow which may otherwise occur at the gaps between grate plates (simply referred to as 'grate') and a pusher at the position through which clinker is charged from a kiln.

This clinker cooling device has such a scheme that, because clinker 11 is cooled by air under conveyance, mobile grates 5a and stationary grates 5b are arranged alternately, air is blown off upward via air feed chambers 13 inside the respective grates, and air is blown from an air chamber 16 under the grates into the gaps between the grates and the gap between the mobile grates 5a and the pusher 18; wherein there are also furnished a nozzle 22 from which air is blown into the gap between the pusher and the mobile grates 5a, a piping 23 connecting the nozzle 22 and a blower 14 to each other via a solenoid valve 24, a detector 25 for detecting the pressure P1 inside the respective air feed chambers 13, a detector 26 for detecting the pressure P2 inside the air chamber 16 communicating with the blower (not shown in the figure), and an operative device 21 for on/off control of the solenoid valve 24 based on P7 and P2.