A block connector is provide to facilitate a disengaging operation. The block connector invention is constructed by placing an upper housing A and a lower housing B one over the other. Lock projections A7, A8 are provided at front and rear sides of the left and right side surfaces of the upper housing A, and corresponding lock holes B3, B5 are provided in the lower housing B. The lock projections A7, A8 are formed with locking surfaces A7b, A8b and disengagement guide surfaces A7c, A8c for smoothly disengaging the lock projections A7, A8 from the lock holes B3, B5. Further, jig insertion holes B6 for inserting a disengaging jig E are formed in the front surface of the lower housing B. The lock projection A7 and the lock hole B3 can be disengaged by inserting the disengaging jig E into the jig insertion hole B6 and prizing the jig insertion hole B6 with the disengaging jig E. Thereafter, if the forcibly opened front ends of the housings A, B are rotated about the rear ends thereof, the lock projections A8 and the lock holes B5 can be disengaged.