An image processing device is capable of executing a plurality of functions. The image processing device includes a preliminary operation execution section, a determination section, and an operation control section. The operation control section allows, where a determination result by the determination section is that preliminary operation is executable, the preliminary operation execution section to execute the preliminary operation when an instruction not being specified to be followed by execution of the main operation is input, and inhibits, where a determination result by the determination section is that preliminary operation is non-executable, the preliminary operation execution section from executing the preliminary operation when an instruction having a possibility of not being followed by execution of the main operation is input.