The present disclosure relates to an apparatus and a method of detecting when a wall mounted drum type washing machine drops, slips, tilts or detaches from the wall, in which the apparatus includes a horizontality detecting sensor configured to output a sensor value corresponding to a horizontal inclination of a main body of a washing machine; a verticality detecting sensor configured to output a sensor value corresponding to a vertical inclination of the main body of the washing machine; and a controller configured to determine whether the main body of the washing machine has dropped, slips, tilts or detaches from the wall by receiving sensor values from the horizontality detecting sensor and the verticality detecting sensor, and blocking power to the washing machine when the main body of the washing machine dropped, slipped, tilted or detached from the wall.