Noise monitoring device and noise monitoring method

Provided is a technique capable of coping with identifying on-the-ground noise generated from an airplane or the like even under a complicated noise environment such as around an airport. A microphone unit (10) is placed within an airport, and window areas (Wa to Wc) are individually specified for each of noise generation source areas such as, for example, an aircraft parking area (20), a taxing runway (30), and an engine test run area (60). By using the microphone unit (10) to perform a sound identification by a three x/y/z-axis correlation method, direction-of-arrival vectors of the on-the-ground noise can also be calculated. If the window areas (Wa to Wc) are specified from the positional relationship between a monitoring point (P) and an area where noise is actually generated, it is possible to identify from the proportions of the direction-of-arrival vectors which of the window areas (Wa to Wc) generates the on-the-ground noise.