An image processing apparatus including: a first interface; a second interface configured to be connected with a server configured to perform user authentication; an image processing unit configured to execute a job including image processing; and a control device configured to: receive authentication information of a user via the first interface; transmit the received authentication information to the server via the second interface; execute a specific operation after receiving the authentication information, the specific operation being a part of the job; receive a result of the user authentication from the server after executing the specific operation; determine whether the user authentication by the server has been successful in accordance with the received result; and execute the rest of the job after completing the specific operation and determining that the user authentication has been successful.