The hydraulic riveter has been accomplished under the circumstances in view. It is one object of the hydraulic riveter to provide a manual hydraulic riveter, which uses the characteristics of check valve and relief valve to facilitate the operation, enabling the user to drive the riveting unit with less effort. To achieve this and other objects of the hydraulic riveter, the manual hydraulic riveter comprises a body, which holds a fluid cylinder, a fluid tank and a hydraulic cylinder, a first piston mounted in the fluid cylinder and movable between two opposite ends of the fluid cylinder, a lever pivoted to the body and adapted to move the first piston in the fluid cylinder between the two opposite ends of the fluid cylinder, a first fluid pipe connected between the fluid cylinder and the hydraulic cylinder, a first check valve mounted in the first fluid pipe, a second fluid pipe connected between the fluid tank and the hydraulic cylinder, a second check valve mounted in the second fluid pipe, a third fluid pipe connected between the hydraulic cylinder and the fluid tank, a relief valve mounted in the third fluid pipe, an actuating rod axially movably and rotatably mounted in the body and partially extending out of the body for mounting a riveting unit, a second piston fixedly mounted on the actuating rod in the hydraulic cylinder and movable between two opposite ends of the hydraulic cylinder, and spring means mounted on the actuating rod inside the hydraulic cylinder and stopped between one end of the hydraulic cylinder and the second piston to impart a forward pressure to the second piston.