A high-pressure pump to be installed in an internal-combustion engine having a cam shaft, comprising: a rocker arm which is mounted on a cam provided on the cam shaft of the internal-combustion engine, and which rocks in association with a rotation of the cam; a pivot which protrudes downward, and the protruding end part of which supports the rocker arm in a rockable manner; a plunger which reciprocates in a top-bottom direction in association with a movement of the rocker arm; and a mounting member (100; 200; 300) which is fixed at a predetermined position, wherein the rocker arm comprises: a roller which rotates on an axis parallel to the cam shaft, and which rolls on the outer circumferential surface of the cam; and an arm body which supports the roller in a rotatable manner, wherein the arm body comprises: a roller-attached part to which the roller is attached; a first end which protrudes from the roller-attached part in a direction perpendicular to the axis of the roller, and which comes in contact with the bottom end part of the plunger from below; and a second end which protrudes from the roller-attached part in a direction opposite to the first end, and which comes in contact with the protruding end part of the pivot from below, wherein the second end has a concave which is recessed downward, and in which the pivot is provided, characterized in that the mounting member (100; 200; 300) comprises a supporting part (120; 210; 320), wherein in a state where the plunger comes out of contact with the first end, the supporting part (120; 210); 320) comes into contact with the arm body so as to resist a turn of the rocker arm around the roller under the weight of the rocker arm and keeps such an attitude of the rocker arm that the protruding end part of the pivot is positioned within the concave of the second end and that the outer circumferential surface of the protruding end part of the pivot is apart from the inner circumferential surface of the concave, and wherein in a state where the plunger comes into contact with the first end, the supporting part (120; 210; 320) comes out of contact with the arm body when the rocker arm turns reversely to the turn under the weight of the rocker arm. a rocker arm which is mounted on a cam provided on the cam shaft of the internal-combustion engine, and which rocks in association with a rotation of the cam; a pivot which protrudes downward, and the protruding end part of which supports the rocker arm in a rockable manner; a plunger which reciprocates in a top-bottom direction in association with a movement of the rocker arm; and a mounting member (100; 200; 300) which is fixed at a predetermined position, wherein the rocker arm comprises: a roller which rotates on an axis parallel to the cam shaft, and which rolls on the outer circumferential surface of the cam; and an arm body which supports the roller in a rotatable manner, wherein the arm body comprises: a roller-attached part to which the roller is attached; a first end which protrudes from the roller-attached part in a direction perpendicular to the axis of the roller, and which comes in contact with the bottom end part of the plunger from below; and a second end which protrudes from the roller-attached part in a direction opposite to the first end, and which comes in contact with the protruding end part of the pivot from below, wherein the second end has a concave which is recessed downward, and in which the pivot is provided, a roller which rotates on an axis parallel to the cam shaft, and which rolls on the outer circumferential surface of the cam; and an arm body which supports the roller in a rotatable manner, wherein the arm body comprises: a roller-attached part to which the roller is attached; a first end which protrudes from the roller-attached part in a direction perpendicular to the axis of the roller, and which comes in contact with the bottom end part of the plunger from below; and a second end which protrudes from the roller-attached part in a direction opposite to the first end, and which comes in contact with the protruding end part of the pivot from below, wherein the second end has a concave which is recessed downward, and in which the pivot is provided, a roller-attached part to which the roller is attached; a first end which protrudes from the roller-attached part in a direction perpendicular to the axis of the roller, and which comes in contact with the bottom end part of the plunger from below; and a second end which protrudes from the roller-attached part in a direction opposite to the first end, and which comes in contact with the protruding end part of the pivot from below, wherein the second end has a concave which is recessed downward, and in which the pivot is provided, characterized in that the mounting member (100; 200; 300) comprises a supporting part (120; 210; 320), wherein in a state where the plunger comes out of contact with the first end, the supporting part (120; 210); 320) comes into contact with the arm body so as to resist a turn of the rocker arm around the roller under the weight of the rocker arm and keeps such an attitude of the rocker arm that the protruding end part of the pivot is positioned within the concave of the second end and that the outer circumferential surface of the protruding end part of the pivot is apart from the inner circumferential surface of the concave, and wherein in a state where the plunger comes into contact with the first end, the supporting part (120; 210; 320) comes out of contact with the arm body when the rocker arm turns reversely to the turn under the weight of the rocker arm.