A throttle grip apparatus comprising: a throttle grip which is configured to be rotatable by a driver from an initial position in a normal direction (a) which is a predetermined direction and a reverse direction (b) which is an opposite direction to the predetermined direction; an interlocking member which includes a plurality of engaged parts configured to be engaged with a plurality of engaging parts (Ga) formed on the throttle grip and is rotatable in conjunction with rotation of the throttle grip in the normal direction (a) and the reverse direction (b); a case which is configured to rotatably hold the interlocking member; a first biasing unit which is configured to bias the interlocking member toward an initial position when the throttle grip rotates in the normal direction (a); a second biasing unit which is configured to bias the interlocking member toward the initial position when the throttle grip rotates in the reverse direction (b); and a rotation angle detecting unit which is configured to detect an rotation angle of the throttle grip by detecting an rotation angle of the interlocking member, wherein the throttle grip apparatus is configured to control an engine of a vehicle according to the rotation angle of the throttle grip detected during rotation of the throttle grip in the normal direction (a) by the rotation angle detecting unit and is configured to activate or stop a predetermined function of the vehicle when the throttle grip rotates in the reverse direction (b), and wherein the plurality of engaging parts (Ga) and the plurality of engaged parts are formed respectively on the throttle grip and the interlocking member at regular intervals along a rotation direction of the throttle grip, and the second biasing unit is installed at each of positions between the engaged parts of the interlocking member. a throttle grip which is configured to be rotatable by a driver from an initial position in a normal direction (a) which is a predetermined direction and a reverse direction (b) which is an opposite direction to the predetermined direction; an interlocking member which includes a plurality of engaged parts configured to be engaged with a plurality of engaging parts (Ga) formed on the throttle grip and is rotatable in conjunction with rotation of the throttle grip in the normal direction (a) and the reverse direction (b); a case which is configured to rotatably hold the interlocking member; a first biasing unit which is configured to bias the interlocking member toward an initial position when the throttle grip rotates in the normal direction (a); a second biasing unit which is configured to bias the interlocking member toward the initial position when the throttle grip rotates in the reverse direction (b); and a rotation angle detecting unit which is configured to detect an rotation angle of the throttle grip by detecting an rotation angle of the interlocking member, wherein the throttle grip apparatus is configured to control an engine of a vehicle according to the rotation angle of the throttle grip detected during rotation of the throttle grip in the normal direction (a) by the rotation angle detecting unit and is configured to activate or stop a predetermined function of the vehicle when the throttle grip rotates in the reverse direction (b), and wherein the plurality of engaging parts (Ga) and the plurality of engaged parts are formed respectively on the throttle grip and the interlocking member at regular intervals along a rotation direction of the throttle grip, and the second biasing unit is installed at each of positions between the engaged parts of the interlocking member.