A connecter assembly comprising a male connecter and a female connecter which are connected to each other, wherein the male connecter includes: a connecter main body; an engagement member, the whole of which is in a substantially cylindrical shape, and which has a support portion which fixedly supports the connecter main body inside, a plurality of claw portions engaging with the female connecter, and a plurality of slit portions provided between the plurality of claw portions; and characterized in that it further comprises a lock member, the whole of which is in a substantially cylindrical shape, and which is disposed outside the engagement member and has a plurality of ribs, slidably inserted to each of the plurality of slit portions of the engagement member, inside, the female connecter includes: a main body portion, the whole of which is in a substantially cylindrical shape, and which has a plurality of flange portions protruding in a radially outward direction so as to be engaged with each of the plurality of claw portions of the engagement member of the male connecter, and a plurality of non-flange portions which are provided between the plurality of flange portions, and when compared to the flange portion, bulged in the radially outward direction over the entire axial direction, and the male connecter and the female connecter are configured such that, when the male connecter is connected to the female connecter, the connecter main body of the male connecter is connected to the female connecter, and each of the plurality of claw portions of the engagement member of the male connecter engages with each of the plurality of flange portions of the main body portion of the female connecter, thereby the male connecter is fixed to the female connecter. a connecter main body; an engagement member, the whole of which is in a substantially cylindrical shape, and which has a support portion which fixedly supports the connecter main body inside, a plurality of claw portions engaging with the female connecter, and a plurality of slit portions provided between the plurality of claw portions; and characterized in that it further comprises a lock member, the whole of which is in a substantially cylindrical shape, and which is disposed outside the engagement member and has a plurality of ribs, slidably inserted to each of the plurality of slit portions of the engagement member, inside, the female connecter includes: a main body portion, the whole of which is in a substantially cylindrical shape, and which has a plurality of flange portions protruding in a radially outward direction so as to be engaged with each of the plurality of claw portions of the engagement member of the male connecter, and a plurality of non-flange portions which are provided between the plurality of flange portions, and when compared to the flange portion, bulged in the radially outward direction over the entire axial direction, and the male connecter and the female connecter are configured such that, when the male connecter is connected to the female connecter, the connecter main body of the male connecter is connected to the female connecter, and each of the plurality of claw portions of the engagement member of the male connecter engages with each of the plurality of flange portions of the main body portion of the female connecter, thereby the male connecter is fixed to the female connecter. a main body portion, the whole of which is in a substantially cylindrical shape, and which has a plurality of flange portions protruding in a radially outward direction so as to be engaged with each of the plurality of claw portions of the engagement member of the male connecter, and a plurality of non-flange portions which are provided between the plurality of flange portions, and when compared to the flange portion, bulged in the radially outward direction over the entire axial direction, and the male connecter and the female connecter are configured such that, when the male connecter is connected to the female connecter, the connecter main body of the male connecter is connected to the female connecter, and each of the plurality of claw portions of the engagement member of the male connecter engages with each of the plurality of flange portions of the main body portion of the female connecter, thereby the male connecter is fixed to the female connecter.