There is provided a paper width detection apparatus including a plurality of lever members lined in parallel in a paper width direction of a recording paper roll, each lever member being rotatably arranged on a same center axis, a detecting unit for detecting a rotation state of the lever member, and a determination unit for determining a paper width of the recording paper roll based on a detection result. One lever member of the plurality of lever members rotates in a first rotating direction about the center axis by contacting an outer peripheral part of a holding unit for holding both ends of the recording paper roll, and another lever member positioned on an inner side in the paper width direction facing the recording paper roll than the lever member contacting the holding unit rotates in conjunction with the lever member contacting the outer peripheral part of the holding unit.