To provide an active type noise reduction device for which a frequency characteristic is not required to set previously and by which a noise can be effectively canceled even if a frequency characteristic is varied with time.

A silencing order selecting section 14 selects a frequency component having the order in which a noise level is high among frequency components being N times (= order) as much as a frequency of explosion of an engine. Concretely, a microphone signal M and a signal (Y.C) multiplying a driving signal Y and a transmission characteristic C together are inputted to an adder 14a, and a noise D (=M-Y.C) at a microphone setting position is obtained by subtracting the latter from the former. And frequency analysis about this noise D is performed by a frequency analyzing section 14b. A selecting section 14c selects a frequency component having the order exceeding the prescribed sound pressure level among peaks of each order frequency component after frequency analysis, and outputs it to a driving signal calculating section 16.