A connector includes a male connector section having a cavity, a female connector section having a cavity to which another male connector section the same as the male connector section can be connected, a male lock section or a female lock section, disposed adjacent to the male connector section so that the connection direction thereof is parallel to that of the male connector section, a female lock section disposed adjacent to the female connector section so that the connection direction thereof is parallel to that of the female connector section, and to which another male lock section the same as the male lock section can be coupled, or a male lock section disposed adjacent to the female connector section so that the connection direction thereof is parallel to that of the female connector section, and to which another female lock section the same as the female lock section can be coupled, and a seal member formed from an elastic material, for maintaining liquid-tightness of the connection between the other male connector section and the female connector section in a locked condition where the other male lock section and the female lock section are coupled to each other, wherein an unlocking sound, which enables recognition of unlocking, is generated at a time of unlocking when the locked condition is released.
