An air sterilizing chamber (23) is proposed which can effectively sterilize air to be brought into contact with drinking water in a water server. The sterilizing chamber includes a case (26) having an air inlet port (24) and an air outlet port (25), and defining an air compartment (27), an air inlet passage (28) through which the air compartment (27) communicate with the air inlet port (24), and an air outlet passage (29) through which the air compartment (27) communicates with the air outlet port (25). The sterilizing chamber further includes an ozone generator (30) mounted in the air compartment (27) and capable of converting oxygen in the air compartment (27) to ozone, an inlet-side ozone-decomposing filter (32) mounted in the air inlet passage (28) at a higher level than the air compartment (27), and an outlet-side ozone-decomposing filter mounted in the air outlet passage (29) at a higher level than the air compartment (27).