An image forming apparatus configured to execute image forming processing based on image data, comprising: a first authentication portion, that shifts a state of the image forming apparatus to a login state in accordance with a first login operation in which login information including an ID and a password of a user is input; a human body detecting portion that detects a human body within a predetermined range from the image forming apparatus; a de-authentication portion, that when a human body is not being detected by the human body detecting portion during the login state and an error has occurred in the image forming apparatus, stores the login information and job information concerning the content of a job set up in a storage portion (7, 54) and cancels the login state, and that when a human body is not being detected by the human body detecting portion during the login state and no error has occurred in the image forming apparatus, cancels the login state; a job storage control portion that stores in a storage portion job setup information concerning content of the image forming processing set up during the login state when the login state is cancelled by the de-authentication portion; and a job restart portion that is configured to, after the login state is cancelled by the de-authentication portion while an error has occurred in the information processing apparatus and subsequently been eliminated, and before a next first login operation is started, shift the state of the image forming apparatus to the login state and restart the job interrupted due to the occurrence of the error based on the job setup information stored in the storage portion in accordance with a job restart operation, the job restart operation involving less operation steps than the first login operation and involving only an input of the password, wherein the job restart portion authenticates the user in accordance with the password input in the job restart operation and the login information stored by the de-authentication portion; and wherein the job setup information includes print count, print size, enlargement and reduction, 2 in 1 printing, and density in the image forming processing. a first authentication portion, that shifts a state of the image forming apparatus to a login state in accordance with a first login operation in which login information including an ID and a password of a user is input; a human body detecting portion that detects a human body within a predetermined range from the image forming apparatus; a de-authentication portion, that when a human body is not being detected by the human body detecting portion during the login state and an error has occurred in the image forming apparatus, stores the login information and job information concerning the content of a job set up in a storage portion (7, 54) and cancels the login state, and that when a human body is not being detected by the human body detecting portion during the login state and no error has occurred in the image forming apparatus, cancels the login state; a job storage control portion that stores in a storage portion job setup information concerning content of the image forming processing set up during the login state when the login state is cancelled by the de-authentication portion; and a job restart portion that is configured to, after the login state is cancelled by the de-authentication portion while an error has occurred in the information processing apparatus and subsequently been eliminated, and before a next first login operation is started, shift the state of the image forming apparatus to the login state and restart the job interrupted due to the occurrence of the error based on the job setup information stored in the storage portion in accordance with a job restart operation, the job restart operation involving less operation steps than the first login operation and involving only an input of the password, wherein the job restart portion authenticates the user in accordance with the password input in the job restart operation and the login information stored by the de-authentication portion; and wherein the job setup information includes print count, print size, enlargement and reduction, 2 in 1 printing, and density in the image forming processing.