PURPOSE: To provide a block for branching the liquid capable of freely changing the direction of the branched passage even after a plurality of blocks provided with the branched passage are connected and mounted on the main supply tube.

CONSTITUTION: A connection part 4 is extended on the side of one of the opening parts of the main passage 1 of a block 1 provided with the main passage 2 and the branched passage 3, and a supporting part 7 of an O-ring 6 for sealing, a male screw part for connection, and a neck part 9 are provided on the outer circumference of the connection part 4 from the side of the opening end part 31. In addition, a seal inner circumferential part 10 to which the connection part 4 of the same block 1 can be fitted, and which is brought into close contact with the O-ring 6 to the end, a female screw part 11 to be screwed with the male screw part 8 on the inlet side, and an annular groove 12 which has the substantially same diameter as that of the ridge part of the male screw part 8 and the width H equivalent to the effective length L of the male screw part 8 between the inner circumferential part of this seal and the female screw part 11.