A method of monitoring a semiconductor fabrication facility and a semiconductor fabrication facility are provided. The method includes collecting an ambient air in a clean room through a plurality of gas lines with their gas inlets arranged at a plurality of sampling positions in the clean room. The method also includes measuring a parameter of the ambient air by a plurality of metrology devices which are connected to the gas lines. At least two of the sampling positions are measured simultaneously. The method further includes issuing a warning when the parameter detected by the metrology devices is outside a range of acceptable values.