1. An image data processing device configured to perform at least two functions, the image data processing device comprising: a plurality of image data treating units configured to treat image data, wherein each of the at least two functions is based on a processing combination of at least one of the plurality image data treating units, and wherein the at least two functions comprise a copier function and a scanner function; a storing unit that stores a plurality of conditions relating to a property of image data to be treated by each of the image data treating units; and a setting unit configured to set, to each of at least two of the image data treating units corresponding to the at least two functions, a corresponding one of the plurality of conditions stored in the storing unit at a time, such that an operating condition for a processing combination of the copier function and an operating condition for the processing combination of the scanner function are set at the time, at least two of the plurality of conditions, each of which is set to the at least two of the image data treating units, being associated with one another so that the at least two of the image data treating units treat respective image data with a same concept of processing.