An image-forming apparatus, comprising: an image formation section for forming an image; a placement unit on which a plurality of sheets of paper to be used in printing are placed; a paper feed rotating body for feeding the paper having been placed on the placement unit toward the image formation section; a detecting body for detecting the arrival of the paper having been supplied by the paper feed rotating body, the detecting body being provided to a paper conveyance path between the image formation section and the paper feed rotating body; a storage unit (82, 91) for storing measurement data that is based on a measurement time, which is a time from the start of paper feeding due to the start of rotation of the paper feed rotating body to when the detecting body detects the arrival of the paper; and a determination unit for finding the average time of the measurement times; establishing as the paper-non-feed jam detection time a time obtained by adding the absolute value of the time difference (ΔT) between the average time and a theoretical time that is predetermined for the measurement times to a detection reference time that is predetermined as a reference for the paper-non-feed jam detection time when the average time is longer than the theoretical time; and determining that a paper-non-feed jam has occurred when the time from the start of paper feeding to when the detecting body detects the arrival of the paper is longer than the established paper-non-feed jam detection time; and a notification unit for providing a notification, wherein the notification unit and the determination unit are adapted as follows: when the average time is longer than the theoretical time and the absolute value is greater than the predetermined acceptable value, - the notification unit produces a notification for prompting maintenance relating to paper feeding, and - the determination unit establishes the detection reference time as the paper-non-feed jam detection time and determines whether or not a paper-non-feed jam has occurred. an image formation section for forming an image; a placement unit on which a plurality of sheets of paper to be used in printing are placed; a paper feed rotating body for feeding the paper having been placed on the placement unit toward the image formation section; a detecting body for detecting the arrival of the paper having been supplied by the paper feed rotating body, the detecting body being provided to a paper conveyance path between the image formation section and the paper feed rotating body; a storage unit (82, 91) for storing measurement data that is based on a measurement time, which is a time from the start of paper feeding due to the start of rotation of the paper feed rotating body to when the detecting body detects the arrival of the paper; and a determination unit for finding the average time of the measurement times; establishing as the paper-non-feed jam detection time a time obtained by adding the absolute value of the time difference (ΔT) between the average time and a theoretical time that is predetermined for the measurement times to a detection reference time that is predetermined as a reference for the paper-non-feed jam detection time when the average time is longer than the theoretical time; and determining that a paper-non-feed jam has occurred when the time from the start of paper feeding to when the detecting body detects the arrival of the paper is longer than the established paper-non-feed jam detection time; and a notification unit for providing a notification, wherein the notification unit and the determination unit are adapted as follows: when the average time is longer than the theoretical time and the absolute value is greater than the predetermined acceptable value, - the notification unit produces a notification for prompting maintenance relating to paper feeding, and - the determination unit establishes the detection reference time as the paper-non-feed jam detection time and determines whether or not a paper-non-feed jam has occurred. - the notification unit produces a notification for prompting maintenance relating to paper feeding, and - the determination unit establishes the detection reference time as the paper-non-feed jam detection time and determines whether or not a paper-non-feed jam has occurred.