A member joining method includes: a placement process of arranging a first member and a second member inserted into the first member so that a gap surrounding the second member is provided between the first member and the second member; a filling process of filling a molten resin into the gap and applying pressure to the resin so as to cause at least one member of the first member or the second member to undergo elastic deformation; and a pressure maintaining process of maintaining the pressure until the resin that has been filled into the gap has cured.