A connector includes a first port, a second port, a first sealing member and a second sealing member. The first port and the first pipe sleeve portion are connected with each other such that at least a part of the first port and at least a part of the first pipe sleeve portion engage with each other by fitting and overlap with each other, and a first sealing member is positioned between two overlapping portions. The second port and the second pipe sleeve portion are connected with each other such that at least a part of the second port and at least a part of the second pipe sleeve portion engage with each other by fitting and push each other, and a second sealing member is positioned between two pushing portions.