A cleaner, comprising: a cleaner main body having a controller; a support member detachably coupled to a module mounting portion of the cleaner main body; and a mop module rotatably supported on the support member, wherein the mop module comprises: a rotating rod configured to be rotatable in at least one direction by being interlocked with a rotation driving portion provided in the module mounting portion when the support member is mounted on the module mounting portion; and a mop member formed to surround an outer circumference of the rotating rod so as to mop the floor in response to the rotation of the rotating rod, wherein the rotating rod is provided with a water receiving portion formed therein, and wherein a water outlet communicating with the water receiving portion is formed through the outer circumference of the rotating rod, characterized in that the outer circumference of the rotating rod is divided into a first part having the water outlet and a second part (121") without the water outlet along the circumference, and wherein the controller is configured to stop the rotation of the rotating rod in a state where the first part is positioned above the second part (121") by using the sensing unit. a cleaner main body having a controller; a support member detachably coupled to a module mounting portion of the cleaner main body; and a mop module rotatably supported on the support member, wherein the mop module comprises: a rotating rod configured to be rotatable in at least one direction by being interlocked with a rotation driving portion provided in the module mounting portion when the support member is mounted on the module mounting portion; and a mop member formed to surround an outer circumference of the rotating rod so as to mop the floor in response to the rotation of the rotating rod, wherein the rotating rod is provided with a water receiving portion formed therein, and wherein a water outlet communicating with the water receiving portion is formed through the outer circumference of the rotating rod, characterized in that the outer circumference of the rotating rod is divided into a first part having the water outlet and a second part (121") without the water outlet along the circumference, and wherein the controller is configured to stop the rotation of the rotating rod in a state where the first part is positioned above the second part (121") by using the sensing unit. a rotating rod configured to be rotatable in at least one direction by being interlocked with a rotation driving portion provided in the module mounting portion when the support member is mounted on the module mounting portion; and a mop member formed to surround an outer circumference of the rotating rod so as to mop the floor in response to the rotation of the rotating rod, wherein the rotating rod is provided with a water receiving portion formed therein, and wherein a water outlet communicating with the water receiving portion is formed through the outer circumference of the rotating rod, characterized in that the outer circumference of the rotating rod is divided into a first part having the water outlet and a second part (121") without the water outlet along the circumference, and wherein the controller is configured to stop the rotation of the rotating rod in a state where the first part is positioned above the second part (121") by using the sensing unit.