PROBLEM TO BE SOLVED: To improve operability of a lock release motion while a male connector is stably retained, and to prevent unintentional cancellation of a locked state when tensile force exerts on the male connector.SOLUTION: A male connector 1 includes: a hood 20 enclosing a periphery of a male luer 10 and a single lock lever 30 of a cantilever supporting structure. The lock lever is arranged to be in parallel with the male luer by placing a free end 30a on the distal end side of the male luer 10 and a fixed end 30b on the proximal end side of the male luer. The lock lever has a claw 34 engaging to a female connector. On an engaging surface 34b of the claw, a fitting structure 34p for the female connector is formed. An operational arm 35 protrudes from a surface on the side opposite to the male luer, of the lock lever, and extends to the fixed end side. When pressing force in a direction to the male luer is applied on a tip end of the operational arm, the lock lever is elastically displaced so that the claw is separated from the male luer.
