To provide a compact air valve with a built-in repairing valve capable of rapidly exhausting air, completely stopping water at repairing time, requiring no wide space for installation.

In this air valve where a large communicating port 5 and a small communicating port 6 for communicating with a pipeline connecting port 4 are arranged in a valve chest 3 arranged inside a valve casing 1, an air valve hole 10 is arranged in an upper part of the valve chest 3, and the air valve hole 10 is opened and closed by a flat valve 17 housed in the valve chest 3, a repairing valve housing part 22 is arranged between the pipeline connecting port 4 and a lower part of a guide member 2. A cylindrical repairing valve element 23 is vertically movably housed. A valve seat 26 is arranged on an under surface of the guide member 2. A passage inlet 25 is arranged between the upper end of the repairing valve housing part 22 and an under surface of the valve chest 3. The passage inlet 25 is opened and closed by driving the repairing valve element 23 in the vertical direction to thereby form a rapidly exhausting passage reaching the air valve hole 10 via the large communicating port 5 from the passage inlet 25 at ordinary time, and the repairing valve element 23 is pressed to the valve seat 26 at repairing time to completely stop water.