There is provided an insertion and withdrawal connector apparatus in which a plurality of connectors can move only in a range of capable of engaging and separating with and from a plurality of mating connectors within a connector receiving body. A connector receiving body (1) has a pair of parallel frames (3), a pair of frame blocks (4) positioned at both end portions, and a plurality of partition members (5). One connector (10) and one mating connector are received in each of a plurality of space portions, that is, receiving chambers partitioned by a pair of frames, a pair of frame blocks, and a plurality of partition members. Each of the partition members has a pair of lances (5f, 5g) having a spring characteristic and each of the connectors has a pair of interlocking groove portions (10g) on both side surfaces. The lance (5f) interlocks with the interlocking groove portion on one of the side surfaces in the connector, and the lance (5g) interlocks with the interlocking groove portion on the other of the side surfaces in the connector. Each of the connectors has a convex portion (10d) at an upper end portion on one of the side surfaces and at a lower end portion on the other of the side surfaces, and each of the convex portions interlocks with each of the partition members.