An elastic member and a waterproof connector are provided and are capable of maintaining water proofing properties even though a wire is shaken. The elastic member (20) is to be fit on a rear surface of a housing (10) capable of housing terminal metal pieces (T) fixed to end portions of wires (W). Seal holes (21) penetrate the elastic member (20) in forward and backward directions and are capable of being in tight contact with the wires (W). Lips (22) are formed to be aligned in the forward and backward directions in the seal holes (21). Grooves (30) open in the front surface and are formed around the seal holes (21). The grooves (30) have a depth enough to reach backward of the lip (22A) located on at least the front surface.