A touch sensor assembly may include a sensor housing disposed at a bottom surface of an exterior member of a household appliance in which an operation unit on which a user touches is formed; a sensor PCB which is provided inside the sensor housing and has a top surface on which a copper coating or film is formed; a touch sensor, the touch sensor including: a metal plate having a bottom surface in contact with the copper coating or film; and a ceramic element installed on a top surface of the metal plate; a spacer in which a sensor hole is formed at a position corresponding to the sensor and which has a bottom surface attached to a surface of the copper coating or film; a conductive foil attached to a top surface of the spacer and having a bottom surface on which an inner guide line which applies an electric current to the ceramic element and an outer guide line which applies an electric current to the metal plate are printed; and a contact portion formed to protrude from a top surface of the conductive foil corresponding to a position of the inner guide line.