There is provided a technique in which in a sheet processing apparatus including a switchback portion in a sheet transport path, a contribution can be made to the improvement of maintenance in the case where a sheet jam occurs in the vicinity of a switchback position. In a sheet processing method of a sheet processing apparatus for performing a specified process to a sheet, the sheet processing apparatus includes a first sheet transport path for transporting the sheet, and a second sheet transport path that is for performing switchback transport of the sheet transported in the first sheet transport path and includes at least one of a hole, a projection and a recess in the vicinity of a meeting position between the second sheet transport path and the first sheet transport path, and the first sheet transport path and the second sheet transport path are enabled to be integrally pulled out to the outside of the sheet processing apparatus.