The invention prevents an LC type optical connector plug from seriously harming a body of a worker, particularly eyes of the worker in a work for fitting the LC type optical connector plug having various concavo-convex shapes. A connector housing (1) has in its inner side of a side wall a guide groove line (7a, 7b, 12) which inserts and guides LC type optical connector plugs (P1, P2) from its fitting portion, and a recess portion (11b) which conforms to a swing motion of a shutter plate (11), and the guide groove line (7a, 7b, 12) is constructed by cutting a part of the guide groove line (7a, 7b, 12) so as to form the same planar shape by forming the recess portion (11b).