An image forming apparatus, comprising: a feed unit configured to supply a base material; a transport mechanism configured to transport the base material supplied from the feed unit along a transport path; a recovery unit configured to recover the base material transported by the transport mechanism along the transport path; a surface reforming unit configured to perform surface reformation processing of reforming a surface of the base material in a first region along the transport path; an image forming unit configured to form an image on a surface reformed in the surface reformation processing on the base material in a second region between the surface reforming unit and the recovery unit along the transport path; and a control unit configured to make the transport mechanism and the image forming unit form an image on the surface of the base material based on image data, wherein the control unit makes the transport mechanism execute a first transport operation of transporting the base material in a first transport direction toward the recovery unit along the transport path and a second transport operation of transporting the base material in a second transport direction toward the feed unit opposite to the first transport direction along the transport path, when the control unit makes the transport mechanism perform the first transport operation of transporting the base material having a formation-completed portion in which an image is formed on a surface by the image forming unit in the first transport direction along the transport path after performing the second transport operation of transporting the base material in the second transport direction along the transport path, the control unit makes the image forming unit form an image on the surface of the base material in such a manner that a multiple surface reforming region, in which a total number of executions of the surface reformation processing in the surface of the base material is larger than a total number of execution of the surface reformation processing in a surrounding region, can be distinguished, and when the control unit makes the image forming unit form a plurality of images so as to be arranged in the first transport direction on the base material, the control unit makes a width in the first transport direction of a portion between images on a one-time surface reforming region on which the surface reformation processing is performed once and a width in the first transport direction of a portion between images on the multiple surface reforming region different from each other. a feed unit configured to supply a base material; a transport mechanism configured to transport the base material supplied from the feed unit along a transport path; a recovery unit configured to recover the base material transported by the transport mechanism along the transport path; a surface reforming unit configured to perform surface reformation processing of reforming a surface of the base material in a first region along the transport path; an image forming unit configured to form an image on a surface reformed in the surface reformation processing on the base material in a second region between the surface reforming unit and the recovery unit along the transport path; and a control unit configured to make the transport mechanism and the image forming unit form an image on the surface of the base material based on image data, wherein the control unit makes the transport mechanism execute a first transport operation of transporting the base material in a first transport direction toward the recovery unit along the transport path and a second transport operation of transporting the base material in a second transport direction toward the feed unit opposite to the first transport direction along the transport path, when the control unit makes the transport mechanism perform the first transport operation of transporting the base material having a formation-completed portion in which an image is formed on a surface by the image forming unit in the first transport direction along the transport path after performing the second transport operation of transporting the base material in the second transport direction along the transport path, the control unit makes the image forming unit form an image on the surface of the base material in such a manner that a multiple surface reforming region, in which a total number of executions of the surface reformation processing in the surface of the base material is larger than a total number of execution of the surface reformation processing in a surrounding region, can be distinguished, and when the control unit makes the image forming unit form a plurality of images so as to be arranged in the first transport direction on the base material, the control unit makes a width in the first transport direction of a portion between images on a one-time surface reforming region on which the surface reformation processing is performed once and a width in the first transport direction of a portion between images on the multiple surface reforming region different from each other.