A plug member is a plug member for covering a liquid injection port for injecting liquid to a liquid container portion of a liquid ejecting apparatus. The plug member includes an elastically deformable plug body, and a holding member that has a higher rigidity than the plug body and is for holding the plug body. The plug body includes a lid part for covering the liquid injection port and a barrel part extending from the lid part to the liquid container portion. The barrel part includes an end portion forming an opening at a side opposite to the lid part, and the holding member includes an engaging portion engageable with a shaft portion for rotating the holding member and a support portion that is provided at an engaging portion side of the end portion and is for supporting the end portion.