Abstract: A connector for connecting a hose or a tube according to the present invention is constituted by a nipple (1), into which the hose (100) can be inserted, a cap nut (10), an inner member (2), a cap (5) and a tapered washer (7), wherein projections (5b) are formed on an outer periphery of the cap (5), a groove (5c) is formed between the projections (5b), and a protrusion (2b) that can engage with an inner periphery of the hose (100) is formed on the inner member (2) or a tubular member (21) in a position corresponding to the projections formed on the outer periphery of the cap.