This essay aims to psychologically analyze two characters, Gus and Ben, in Harold Pinter`s Dumb Waiter in terms of their language and action. For this, some Lacanian terms are used as critical tools; ``ideal ego,`` ``ego ideal,`` ``the imaginary,`` ``the symbolic,`` ``signifier,`` ``signified,`` ``trauma,`` ``empty speech,`` ``full speech,`` and ``object a.`` Some of these are, of course, not Lacan`s original terms. In the basement room which stands for the symbolic controlled by the big Other, master signifier, Wilson, their conversations go around in circles and their actions are repeated to no purpose, with Gus being viewed as the ideal ego in the imaginary using empty speech, and Ben seen as the ego ideal employing full speech. They also, as speech subjects, have to wait for the big Other`s order or decision, when the chain of the signifier is in a tangle. Accordingly their language and actions are seriously affected by the pressure from the big Other. Gus, suffering from that pressure as well as the trauma of killing a girl, is trapped with the narcissistic ego at the mirror phase of the imaginary and shows a tint of insubordination or infidelity to Wilson. That`s why Ben who seeks to solidify the symbolic world for the big Other and himself as well, is doomed to kill his partner Gus. (Kwandong University)