To provide an optical cable junction box that prevents a side pressure from acting on an optical cable.

The optical cable junction box includes: a box 10 that has, on the lower face, introducing holes 11a-11c for introducing at least two optical cables 110a, 110b, 120 and that stores inside the extra portions of the optical cables connected with each other and of the other optical cable; a supporting member 20 that is attached to the box 10 so as to project downward therefrom; a penetration slot 21 formed in the supporting member 20 continuously in a direction crossing each of the optical cables 110a, 110b, 120; and a cable fixing part (cable fixtures 30a-30c) that is attached freely attachably/detachably to an optionally selected position of the penetration slot 21 and that fixes the optical cables 110a, 110b, 120 to the supporting member 20.