A fluid pressure cylinder comprising: a cylinder tube having a central axis and an inner peripheral surface that is cylindrical about the central axis; a piston that is accommodated in the cylinder tube, slides against the inner peripheral surface of the cylinder tube, and defines a fluid chamber (5, 6) within the cylinder tube; and a sealing ring held in a sealing ring accommodation groove formed in a circumferential direction in an outer peripheral surface of the piston; a backup ring that is attached to an outer peripheral surface of the piston; and a bearing ring; characterized by a pair of piston ring accommodation grooves formed respectively in the circumferential direction in the outer peripheral surface of the piston on one side of the sealing ring with respect to a direction of the central axis, the pair of the piston ring accommodation grooves comprising a first groove and a second groove that is located farer from the sealing ring than the first groove; a first piston ring held in the first piston ring accommodation groove, the first piston ring comprising a fractured portion with which a diameter thereof can be increased and reduced; a second piston ring held in the second piston ring accommodation groove, the second piston ring comprising a fractured portion with which a diameter thereof can be increased and reduced; said backup ring being attached between the sealing ring and the first piston ring, the respective ends (13a, 13b) of the backup ring relative to the direction of the central axis respectively contacting the sealing ring and the first piston ring such that the backup ring is accommodated in an annular backup ring accommodation portion defined by an end surface (21 b) of the piston ring close to the sealing ring, an end surface (10a, 10b) of the sealing ring and the outer peripheral surface of the piston; said bearing ring being attached to the outer peripheral surface of the piston between the first and the second piston rings, the respective ends (15a, 15b) of the bearing ring relative to the direction of the central axis respectively contacting the first and second piston rings such that the bearing ring is accommodated in an annular bearing ring accommodation portion defined by an end surface (21 b) of one piston ring, an end surface of another piston ring and the outer peripheral surface of the piston. a cylinder tube having a central axis and an inner peripheral surface that is cylindrical about the central axis; a piston that is accommodated in the cylinder tube, slides against the inner peripheral surface of the cylinder tube, and defines a fluid chamber (5, 6) within the cylinder tube; and a sealing ring held in a sealing ring accommodation groove formed in a circumferential direction in an outer peripheral surface of the piston; a backup ring that is attached to an outer peripheral surface of the piston; and a bearing ring; characterized by a pair of piston ring accommodation grooves formed respectively in the circumferential direction in the outer peripheral surface of the piston on one side of the sealing ring with respect to a direction of the central axis, the pair of the piston ring accommodation grooves comprising a first groove and a second groove that is located farer from the sealing ring than the first groove; a first piston ring held in the first piston ring accommodation groove, the first piston ring comprising a fractured portion with which a diameter thereof can be increased and reduced; a second piston ring held in the second piston ring accommodation groove, the second piston ring comprising a fractured portion with which a diameter thereof can be increased and reduced; said backup ring being attached between the sealing ring and the first piston ring, the respective ends (13a, 13b) of the backup ring relative to the direction of the central axis respectively contacting the sealing ring and the first piston ring such that the backup ring is accommodated in an annular backup ring accommodation portion defined by an end surface (21 b) of the piston ring close to the sealing ring, an end surface (10a, 10b) of the sealing ring and the outer peripheral surface of the piston; said bearing ring being attached to the outer peripheral surface of the piston between the first and the second piston rings, the respective ends (15a, 15b) of the bearing ring relative to the direction of the central axis respectively contacting the first and second piston rings such that the bearing ring is accommodated in an annular bearing ring accommodation portion defined by an end surface (21 b) of one piston ring, an end surface of another piston ring and the outer peripheral surface of the piston.