A shock absorber for a dishwasher includes a tub having a separation-prevention member protruding from an inner surface of the tub and a guide rail provided at a lower portion of the separation-prevention member to guide the moving casters and a rack having moving casters configured to facilitate a movement of the rack, the shock absorber comprising: a body ; at least two receiving grooves in a first side surface of the body, wherein the at least two receiving grooves are configured to receive a portion of the rack to restrict rotation of the body , and a pressing portion provided on a second side surface of the body opposite to the first side surface, the pressing portion configured to exert a downward force on the body in response to being pressed against a portion of the tub , wherein the pressing portion is inserted into a space between the separation-prevention member and the guide rail , the separation-prevention member configured to confine a movement of the moving casters in an upward direction and to contact the pressing portion , and wherein the pressing portion is configured to press a lower portion of the separation-prevention member in the upward direction, wherein the pressing portion comprises an upper inclined surface provided at an upper portion of the pressing portion , the upper inclined surface extending outwardly and downwardly from the second side surface of the body , wherein the pressing portion further comprises: a mounting surface provided at a lower portion of the pressing portion , the mounting surface configured to be mounted on the guide rail ; and a lower inclined surface extending inwardly and downwardly from the mounting surface toward the first side surface of the body . a body ; at least two receiving grooves in a first side surface of the body, wherein the at least two receiving grooves are configured to receive a portion of the rack to restrict rotation of the body , and a pressing portion provided on a second side surface of the body opposite to the first side surface, the pressing portion configured to exert a downward force on the body in response to being pressed against a portion of the tub , wherein the pressing portion is inserted into a space between the separation-prevention member and the guide rail , the separation-prevention member configured to confine a movement of the moving casters in an upward direction and to contact the pressing portion , and wherein the pressing portion is configured to press a lower portion of the separation-prevention member in the upward direction, wherein the pressing portion comprises an upper inclined surface provided at an upper portion of the pressing portion , the upper inclined surface extending outwardly and downwardly from the second side surface of the body , wherein the pressing portion further comprises: a mounting surface provided at a lower portion of the pressing portion , the mounting surface configured to be mounted on the guide rail ; and a lower inclined surface extending inwardly and downwardly from the mounting surface toward the first side surface of the body . a mounting surface provided at a lower portion of the pressing portion , the mounting surface configured to be mounted on the guide rail ; and a lower inclined surface extending inwardly and downwardly from the mounting surface toward the first side surface of the body . <EOS>