In a swash plate type hydraulic unit for use as a swash plate type hydraulic pump and a hydraulic motor, a plurality of block plates 41 to 45 being divided at split planes extending orthogonal to a cylinder block axis X are soldered to one another to form a cylinder block 4. Inlet holes 25i and 39i for supporting plungers 27 and 41 slidably therein are formed in an inlet-side one of the block plates 41, 42; 44, 45 located close to plunger swash plates 9a and 19a, while in remaining inner-side ones of the block plates 43 to 45; 41 to 43 are formed inner holes 25o and 39o of a diameter larger than that of the inlet holes 25i and 39i, the inner holes 25o and 39o each defining an oil chamber to which the outer peripheral surface of the associated plunger 27, 41 faces. With this arrangement, a cylinder block structure superior in mass-productivity is provided.