A relief valve, comprising: a valve body including therein an accommodation chamber formed along a central axis, a first port through which a fluid flows into the accommodation chamber, and a second port through which the fluid is discharged from the accommodation chamber; a sleeve formed into a cylindrical hollow shape about the central axis to slidably move along the central axis within the accommodation chamber, the sleeve including an inflow bore connecting to the first port and an outflow bore connecting to the second port, the sleeve having a first end surface which is adjacent to the first port, and a second end surface which is provided in an opposite direction from the first port in a direction of the central axis; a valve receiving a hydraulic pressure of the fluid from the first port and sliding within the sleeve along the central axis to adjoin and separate from the inflow bore, the valve being adjacent to the inflow bore to close the outflow bore and being separated from the inflow bore to open the outflow bore; a biasing member applying a biasing force to the valve in a direction against the hydraulic pressure from the first port; a valve position change mechanism (14, 15, 16) applying the hydraulic pressure to the second end surface to set the sleeve in a low-pressure operation position that is adjacent the first port, the valve position change mechanism releasing the hydraulic pressure applied to the second end surface and setting the sleeve in a high-pressure operation position by the hydraulic pressure acting on the first end surface, the high-pressure operation position being provided in the opposite direction from the first port in the direction of the central axis; and a stopper formed in a position circumferentially around the central axis and determining a movement limiting position of the sleeve toward the high-pressure operation position, characterized in that the stopper includes a plurality of stoppers adjoining one another in the circumferential area around the central axis, the fluid flows between the plurality of stoppers and the hydraulic pressure is applied to the second end surface. a valve body including therein an accommodation chamber formed along a central axis, a first port through which a fluid flows into the accommodation chamber, and a second port through which the fluid is discharged from the accommodation chamber; a sleeve formed into a cylindrical hollow shape about the central axis to slidably move along the central axis within the accommodation chamber, the sleeve including an inflow bore connecting to the first port and an outflow bore connecting to the second port, the sleeve having a first end surface which is adjacent to the first port, and a second end surface which is provided in an opposite direction from the first port in a direction of the central axis; a valve receiving a hydraulic pressure of the fluid from the first port and sliding within the sleeve along the central axis to adjoin and separate from the inflow bore, the valve being adjacent to the inflow bore to close the outflow bore and being separated from the inflow bore to open the outflow bore; a biasing member applying a biasing force to the valve in a direction against the hydraulic pressure from the first port; a valve position change mechanism (14, 15, 16) applying the hydraulic pressure to the second end surface to set the sleeve in a low-pressure operation position that is adjacent the first port, the valve position change mechanism releasing the hydraulic pressure applied to the second end surface and setting the sleeve in a high-pressure operation position by the hydraulic pressure acting on the first end surface, the high-pressure operation position being provided in the opposite direction from the first port in the direction of the central axis; and a stopper formed in a position circumferentially around the central axis and determining a movement limiting position of the sleeve toward the high-pressure operation position, characterized in that the stopper includes a plurality of stoppers adjoining one another in the circumferential area around the central axis, the fluid flows between the plurality of stoppers and the hydraulic pressure is applied to the second end surface.