PURPOSE: To simplify an attaching device and a mechanism of a secondary control valve for an externally attached working machine in a tractor for attaching the secondary control valve on a hydraulic case.

CONSTITUTION: An apparatus for delivering hydraulic pressure externally in a tractor is constructed in such a manner that plural fixing bolts 3 are fixed on a hydraulic case 2 placed on a mission case 1 and one to several hydraulic control valves 4, 5 or spacers 6 of a same thickness, a valve cover 7 for covering outside of the valves and a lever bracket 8 are layered in due order on the bolts 3 and fastened together with nuts 9 from the outside.