To provide a vacuum breaker including a pressure gauge that is hardly affected by vacuum.

In a valve casing 1 having an inflow port 2 to be connected to a fluid piping system (unillustrated) and an open air port 3 to be opened to open air, a valve chest 6 is formed to communicate with the inflow port 2 and the open air port 3, and a valve element 11 is disposed in the valve chest 6 to normally close the valve chest 6 and the open air port 3 to each other, and open the valve chest 6 and the open air port 3 to each other when the side of the inflow port 2 falls into a vacuum state in this vacuum breaker. A pressure gauge connection port 4 is provided in the valve casing 1 to communicate with the valve chest 6, so that the pressure gauge (unillustrated) is connected.