A washing machine comprising: a cabinet with an opening at an upper portion thereof; an outer tub to be provided in the cabinet; an inner tub to be provided in the outer tub; a motor configured to rotate the inner tub; a camera configured to capture an image of an inside of the inner tub; and a controller configured to: control the motor to increase a rotational speed of the inner tub while provided in the outer tub to a first rotational speed during spinning, control the camera to capture an image of the inside of the inner tub, control the motor to set the rotational speed of the inner tub while provided in the outer tub to a second rotational speed, which is less than the first rotational speed, based on the image of the inside of the inner tub captured by the camera during the spinning, characterized in that the controller is further configured to: set a region of interest, ROI, in a central portion of the image of the inside of the inner tub, control the motor to increase the rotational speed of the inner tub to the first rotational speed in response to the image at the ROI being the same as a predetermined image of a bottom of the inner tub, and control the motor to set the rotational speed of the inner tub to the second rotational speed in response to the image at the ROI being different from a predetermined image of a bottom of the inner tub. a cabinet with an opening at an upper portion thereof; an outer tub to be provided in the cabinet; an inner tub to be provided in the outer tub; a motor configured to rotate the inner tub; a camera configured to capture an image of an inside of the inner tub; and a controller configured to: control the motor to increase a rotational speed of the inner tub while provided in the outer tub to a first rotational speed during spinning, control the camera to capture an image of the inside of the inner tub, control the motor to set the rotational speed of the inner tub while provided in the outer tub to a second rotational speed, which is less than the first rotational speed, based on the image of the inside of the inner tub captured by the camera during the spinning, control the motor to increase a rotational speed of the inner tub while provided in the outer tub to a first rotational speed during spinning, control the camera to capture an image of the inside of the inner tub, control the motor to set the rotational speed of the inner tub while provided in the outer tub to a second rotational speed, which is less than the first rotational speed, based on the image of the inside of the inner tub captured by the camera during the spinning, characterized in that the controller is further configured to: set a region of interest, ROI, in a central portion of the image of the inside of the inner tub, control the motor to increase the rotational speed of the inner tub to the first rotational speed in response to the image at the ROI being the same as a predetermined image of a bottom of the inner tub, and control the motor to set the rotational speed of the inner tub to the second rotational speed in response to the image at the ROI being different from a predetermined image of a bottom of the inner tub. set a region of interest, ROI, in a central portion of the image of the inside of the inner tub, control the motor to increase the rotational speed of the inner tub to the first rotational speed in response to the image at the ROI being the same as a predetermined image of a bottom of the inner tub, and control the motor to set the rotational speed of the inner tub to the second rotational speed in response to the image at the ROI being different from a predetermined image of a bottom of the inner tub.