A noise eliminating device including: an acoustic sensor array including a first acoustic sensor at a vertex forming a vertex angle of an isosceles triangle, and second and third acoustic sensors at the other vertexes of the isosceles triangle, the first sensor being arranged on a bisector between two boundaries between a direction range in which a target sound source can exist and a direction range in which a noise source can exist; and the second and third sensors being arranged so that the boundaries coincide with a direction of a perpendicular bisector of a line segment connecting the first and second sensors, and a direction of a perpendicular bisector of a line segment connecting the first and third sensors; and a processor to use signals output from the sensors to output a signal obtained by enhancing sound from the target sound source and eliminating noise from the noise source.