PURPOSE: To hold a cam plate in a casing with certainty in a variable capacity cam plate hydraulic rotating machine.

CONSTITUTION: A cam plate 29 has a first abutting surface 31 and a second abutting surface 32 on a back side of a flat surface 29A, a crossing line of both of which surfaces 31 and 32 serves as a fulcrum 30. A tilting control plate 33 for holding the cam plate 29 has a first supporting surface 34 against which the first abutting surface 31 abuts and a second supporting surface 35 against which the second abutting surface 32 abuts, a crossing line of both of which surfaces 34, 35 serves as a fulcrum. It is thus possible to hold the cam plate 29 by means of the tilting control plate 33 with certainty when the cam plate 29 shows a minimum tilting angle.