In order to provide an optical transmission device capable of implementing the spectral control of WDM signals while taking into account optical component characteristics, an optical transmission device is provided with: a WSS; a wavelength monitor that outputs a signal expressing a first spectrum, which is the spectrum of the WSS optical output; an optical processing unit that subjects the WSS optical output to prescribed processing; a temperature monitor that outputs a signal indicating the temperature of an optical processing means; and a control unit that receives the input of the signal expressing the first spectrum and the signal indicating the temperature, and controls the transmission characteristics of the WSS on the basis of the first spectrum and the temperature.