To control a focal position of an optical system in a more preferable manner according to a band to be observed.SOLUTION: In the imaging signal corresponding to each of a plurality of mutually different spectral components based on the result of receiving the observation target light from the subject in the living body by the imaging device, the observation target A calculation unit which calculates an evaluation value indicating the degree of focusing on the basis of the imaging signal to which the weight is applied by applying weights between the plurality of spectral components corresponding to the band to be observed And a control unit for controlling the focal position of the optical system by controlling the position of at least one optical member among the optical systems for forming light on the imaging device based on the evaluation value, apparatus.(FIG.【課題】観察の対象となる帯域に応じて、より好適な態様で光学系の焦点位置を制御する。【解決手段】撮像素子による生体内の被写体からの観察対象光の受光結果に基づく、互いに異なる複数の分光成分それぞれに対応する撮像信号に対して、前記観察対象光の帯域のうち観察の対象とする帯域に応じた前記複数の分光成分間の重みを適用し、前記重みが適用された当該撮像信号に基づき、合焦の度合いを示す評価値を算出する算出部と、前記被写体からの観察対象光を前記撮像素子に結像する光学系のうち少なくとも1つの光学部材の位置を、前記評価値に基づき制御することで当該光学系の焦点位置を制御する制御部と、を備える、医療用観察装置。【選択図】図4
