An active noise control system for reducing noise heard by an object, comprising: a microphone; an adaptive filter (1111 to 1113) that is configured to receive a noise signal representing the noise as an input; a speaker that is configured to output an output of the adaptive filter (1111 to 1113) as a noise cancellation sound; a plurality of auxiliary filters for which a respective transfer function (H1(z)-H3(z)) is preset and that are configured to receive the noise signal as an input and are provided corresponding to a plurality of different positions; an error correction unit that is configured to correct a microphone output signal, which is an output of the microphone, using an output of one of the auxiliary filters and to output the corrected microphone output signal to the adaptive filter (1111 to 1113) as an error signal; characterized by a position detection unit that is configured to detect a position of the object; and a switching control unit that is configured to control the error correction unit to output a signal obtained by correcting the microphone output signal using an output of a first of the auxiliary filters and a signal obtained by correcting the microphone output signal using an output of a second of the auxiliary filters as the error signal from the error correction unit at a ratio after switching which is a ratio determined according to a ratio of a distance between a position corresponding to the first of the auxiliary filters and a position of the object and a distance between a position corresponding to the second of the auxiliary filters and the position of the object, using, as the first of the auxiliary filters and the second of the auxiliary filters, two of the auxiliary filters in which two positions corresponding to the two auxiliary filters become the position of the object when the position of the object detected by the position detection unit changes, wherein the adaptive filter (1111 to 1113) is configured to execute a predetermined adaptive algorithm using an error representing an error signal input from the error correction unit and to update a transfer function of the adaptive filter (1111 to 1113), and the transfer function learned as the transfer function in which the error indicated by the error signal becomes 0 is preset in the plurality of the auxiliary filters when the noise is canceled by the noise cancellation sound at the corresponding position. a microphone; an adaptive filter (1111 to 1113) that is configured to receive a noise signal representing the noise as an input; a speaker that is configured to output an output of the adaptive filter (1111 to 1113) as a noise cancellation sound; a plurality of auxiliary filters for which a respective transfer function (H1(z)-H3(z)) is preset and that are configured to receive the noise signal as an input and are provided corresponding to a plurality of different positions; an error correction unit that is configured to correct a microphone output signal, which is an output of the microphone, using an output of one of the auxiliary filters and to output the corrected microphone output signal to the adaptive filter (1111 to 1113) as an error signal; characterized by a position detection unit that is configured to detect a position of the object; and a switching control unit that is configured to control the error correction unit to output a signal obtained by correcting the microphone output signal using an output of a first of the auxiliary filters and a signal obtained by correcting the microphone output signal using an output of a second of the auxiliary filters as the error signal from the error correction unit at a ratio after switching which is a ratio determined according to a ratio of a distance between a position corresponding to the first of the auxiliary filters and a position of the object and a distance between a position corresponding to the second of the auxiliary filters and the position of the object, using, as the first of the auxiliary filters and the second of the auxiliary filters, two of the auxiliary filters in which two positions corresponding to the two auxiliary filters become the position of the object when the position of the object detected by the position detection unit changes, wherein the adaptive filter (1111 to 1113) is configured to execute a predetermined adaptive algorithm using an error representing an error signal input from the error correction unit and to update a transfer function of the adaptive filter (1111 to 1113), and the transfer function learned as the transfer function in which the error indicated by the error signal becomes 0 is preset in the plurality of the auxiliary filters when the noise is canceled by the noise cancellation sound at the corresponding position.