Proposed is a home appliance that includes a cabinet defining an exterior of the home appliance, a reception space defined inside the cabinet and configured to receive objects in the reception space, a door configured to open and close an open surface of the reception space, the door having a viewing window provided at the door, a sensor assembly configured to detect each of a plurality of vibrations transmitted in three axial directions orthogonal to each other and to determine whether one or more of the plurality of vibrations is generated by a user's knock, a lamp configured to illuminate an inside of the reception space, and a controller configured to turn on/off the lamp based on a knock-on signal output by the sensor assembly.