To simplify the constitution of an active noise control device to be applied to three-dimensional (3D) space opening only its ceiling face and to reduce the size and cost of the device.

In a partition 11, only a ceiling face is opened. At least one sensor microphone 15 and plural erasing speakers 16 are arranged so as to be oriented to a noise source 14 in the partition 11. Error microphones 17 are correspondingly arranged so as to be oriented to the erasing speakers 16. An one-dimensional active noise control means 18 modulates a signal having the same amplitude and reverse phase as/to those of a signal detected by the sensor microphone 15 in accordance with an weight coefficient, sends the modulated signal to the speakers 16 and controls the change of the weight coefficient in accordance with a signal obtained by adding error sound signals outputted from respective error microphones 17 by an adder 19. The device is constituted based on experimental discovery that almost the same resonance mode as that of closed 3D space can be obtained even in the 3D space opening only one face.