Organic matter production method, organic matter production process monitoring method, and organic matter production process monitoring device

This organic matter production method whereby it is possible to more suitably ascertain the production process status has: a first step of acquiring an absorption spectrum for an object to be measured by exposing the object to be measured, for which the amount of the raw materials or a desired product varies according to the progress of the production process, to broadband light and thereby receiving transmitted light or scattered and reflected light emitted from the object to be measured; a second step of extracting, using the absorption spectrum, two or more feature quantities indicating characteristics of the object to be measured; and a third step of controlling the production process on the basis of the two or more feature quantities.