A cleaner, comprising: a cleaner body having a module mounting portion; a rotation driving portion provided at one side of the module mounting portion; a supporting member inserted and mounted to the module mounting portion (1 10a), and separated and withdrawn from the module mounting portion (1 10a), through a bottom part of the cleaner body; and a cleaning module coupled to the supporting member so as to be inserted or withdrawn together with the supporting member when the supporting member is inserted or withdrawn, wherein the cleaning module includes: a rotation rod rotatably supported by the supporting member, and coupled to the rotation driving portion by being inserted into the module mounting portion (1 10a); and a cleaning member coupled to an outer circumferential surface of the rotation rod, and configured to clean a floor by being rotated together with the rotation rod when the rotation rod is rotated by a rotation driving force transmitted from the rotation driving portion; characterized in that the rotation rod includes: a rotation coupling member exposed to outside through one end of the rotation rod in an axial direction, and formed to be pressurized toward inside of the rotation rod; and an elastic member configured to provide an elastic force such that the rotation coupling member pressurized toward the inside of the rotation rod is restored to an initial position, wherein the module mounting portion includes an inclined surface formed at a contact position with the rotation coupling member while the cleaning module is being mounted such that the rotation coupling member is slid on a slant surface, the inclined surface being configured to gradually pressurize the rotation coupling member toward the inside of the rotation rod while the cleaning module is being mounted. a cleaner body having a module mounting portion; a rotation driving portion provided at one side of the module mounting portion; a supporting member inserted and mounted to the module mounting portion (1 10a), and separated and withdrawn from the module mounting portion (1 10a), through a bottom part of the cleaner body; and a cleaning module coupled to the supporting member so as to be inserted or withdrawn together with the supporting member when the supporting member is inserted or withdrawn, wherein the cleaning module includes: a rotation rod rotatably supported by the supporting member, and coupled to the rotation driving portion by being inserted into the module mounting portion (1 10a); and a cleaning member coupled to an outer circumferential surface of the rotation rod, and configured to clean a floor by being rotated together with the rotation rod when the rotation rod is rotated by a rotation driving force transmitted from the rotation driving portion; characterized in that the rotation rod includes: a rotation coupling member exposed to outside through one end of the rotation rod in an axial direction, and formed to be pressurized toward inside of the rotation rod; and an elastic member configured to provide an elastic force such that the rotation coupling member pressurized toward the inside of the rotation rod is restored to an initial position, wherein the module mounting portion includes an inclined surface formed at a contact position with the rotation coupling member while the cleaning module is being mounted such that the rotation coupling member is slid on a slant surface, the inclined surface being configured to gradually pressurize the rotation coupling member toward the inside of the rotation rod while the cleaning module is being mounted. a rotation rod rotatably supported by the supporting member, and coupled to the rotation driving portion by being inserted into the module mounting portion (1 10a); and a cleaning member coupled to an outer circumferential surface of the rotation rod, and configured to clean a floor by being rotated together with the rotation rod when the rotation rod is rotated by a rotation driving force transmitted from the rotation driving portion; characterized in that the rotation rod includes: a rotation coupling member exposed to outside through one end of the rotation rod in an axial direction, and formed to be pressurized toward inside of the rotation rod; and an elastic member configured to provide an elastic force such that the rotation coupling member pressurized toward the inside of the rotation rod is restored to an initial position, wherein the module mounting portion includes an inclined surface formed at a contact position with the rotation coupling member while the cleaning module is being mounted such that the rotation coupling member is slid on a slant surface, the inclined surface being configured to gradually pressurize the rotation coupling member toward the inside of the rotation rod while the cleaning module is being mounted. a rotation coupling member exposed to outside through one end of the rotation rod in an axial direction, and formed to be pressurized toward inside of the rotation rod; and an elastic member configured to provide an elastic force such that the rotation coupling member pressurized toward the inside of the rotation rod is restored to an initial position, wherein the module mounting portion includes an inclined surface formed at a contact position with the rotation coupling member while the cleaning module is being mounted such that the rotation coupling member is slid on a slant surface, the inclined surface being configured to gradually pressurize the rotation coupling member toward the inside of the rotation rod while the cleaning module is being mounted.