A plastic bottle processing apparatus that processes a plastic bottle including a plastic bottle body having a label wound thereon and a cap screwed to the plastic bottle body, comprising: an apparatus body having a conveying path section in which the plastic bottle is conveyed along a predetermined conveying direction; and a label separating unit arranged in a middle of the conveying path section so as to separate the label from the plastic bottle body, the conveying path section allowing the plastic bottle to be conveyed in a state where an axial direction of the plastic bottle is parallel to the conveying direction, and the label separating unit including: a label cutting member that cuts the label of the plastic bottle, which is conveyed in the conveying path section along the axial direction of the plastic bottle; a heating member that heats the label cut by the label cutting member; and a brush member disposed so as to be able to make contact with the label heated by the heating member and remove the label from the plastic bottle body by making contact with the label, a rotating device that causes the plastic bottle body and the brush member to rotate relative to each other in a state where the plastic bottle body and the brush member are in contact with each other, wherein the brush member is a rotary brush member (64a to 64d) including a shaft portion extending along the axial direction of the plastic bottle body and a brush bristle arranged on an outer circumference of the shaft portion, and the rotating device rotates the rotary brush member (64a to 64d) by applying rotational driving force to the shaft portion and characterised in that the brush bristle is arranged in a spiral form along the axial direction of the shaft portion. an apparatus body having a conveying path section in which the plastic bottle is conveyed along a predetermined conveying direction; and a label separating unit arranged in a middle of the conveying path section so as to separate the label from the plastic bottle body, the conveying path section allowing the plastic bottle to be conveyed in a state where an axial direction of the plastic bottle is parallel to the conveying direction, and the label separating unit including: a label cutting member that cuts the label of the plastic bottle, which is conveyed in the conveying path section along the axial direction of the plastic bottle; a heating member that heats the label cut by the label cutting member; and a brush member disposed so as to be able to make contact with the label heated by the heating member and remove the label from the plastic bottle body by making contact with the label, a rotating device that causes the plastic bottle body and the brush member to rotate relative to each other in a state where the plastic bottle body and the brush member are in contact with each other, wherein the brush member is a rotary brush member (64a to 64d) including a shaft portion extending along the axial direction of the plastic bottle body and a brush bristle arranged on an outer circumference of the shaft portion, and the rotating device rotates the rotary brush member (64a to 64d) by applying rotational driving force to the shaft portion and characterised in that the brush bristle is arranged in a spiral form along the axial direction of the shaft portion. a label cutting member that cuts the label of the plastic bottle, which is conveyed in the conveying path section along the axial direction of the plastic bottle; a heating member that heats the label cut by the label cutting member; and a brush member disposed so as to be able to make contact with the label heated by the heating member and remove the label from the plastic bottle body by making contact with the label, a rotating device that causes the plastic bottle body and the brush member to rotate relative to each other in a state where the plastic bottle body and the brush member are in contact with each other, wherein the brush member is a rotary brush member (64a to 64d) including a shaft portion extending along the axial direction of the plastic bottle body and a brush bristle arranged on an outer circumference of the shaft portion, and the rotating device rotates the rotary brush member (64a to 64d) by applying rotational driving force to the shaft portion and characterised in that the brush bristle is arranged in a spiral form along the axial direction of the shaft portion.