Washing machine and method for controlling same

A washing machine comprising:

• a tub;
• a drum rotatably installed in the tub;
• a water supply device configured to supply water to the tub;
• a driving portion configured to rotate the drum;
• a water level detector configured to detect a water level in the tub;
• and
• a controller configured to control the water supply device and the driving portion to perform washing operations including a water supply operation, a drainage operation, and a spin-drying operation, wherein the controller is configured to:
• calculate a first water level change rate after start of the water supply operation according to a detection result of the water level detector during the water supply operation,
• calculate a second water level change rate after the first water level change rate is calculated,
• determine, based on a ratio of the second water level change rate to the first water level change rate being greater than a predetermined threshold, whether a laundry within the drum includes a waterproof cloth, before performing the spin-drying operation, and
• control an operation of the driving portion based on the waterproof cloth accommodated in the drum.