An automobile key operation mechanism comprising: a key cylinder ; a locking lever that extends from a side surface of the key cylinder ; an unlocking lever that extends from a side surface of the key cylinder in a direction that is different from the direction in which the locking lever extends; a locking pull line that is configured to lock a door of an automobile; and an unlocking pull line that is configured to unlock the door, wherein one end of the locking pull line is attached to the locking lever , wherein one end of the unlocking pull line is attached to the unlocking lever , and wherein, when the key cylinder rotates in a locking direction, the locking lever pulls the locking pull line , and, when the key cylinder rotates in an unlocking direction that is opposite the locking direction, the unlocking lever pulls the unlocking pull line , and wherein the key operation mechanism further comprises a support component that, when the key cylinder rotates in the locking direction, supports the locking pull line at a position at which the locking lever is at a greater distance away from the support component , and, when the key cylinder rotates in the unlocking direction, supports the unlocking pull line at a position at which the unlocking lever is at a greater distance away from the support component , characterized in that the support component is fixed to a housing and further includes a base plate screwed to an inner surface of the housing , an unlocking cable mounting wall and a locking cable mounting wall , the unlocking cable mounting wall and the locking cable mounting wall both projecting from the base plate toward the inside of the automobile. a key cylinder ; a locking lever that extends from a side surface of the key cylinder ; an unlocking lever that extends from a side surface of the key cylinder in a direction that is different from the direction in which the locking lever extends; a locking pull line that is configured to lock a door of an automobile; and an unlocking pull line that is configured to unlock the door, wherein one end of the locking pull line is attached to the locking lever , wherein one end of the unlocking pull line is attached to the unlocking lever , and wherein, when the key cylinder rotates in a locking direction, the locking lever pulls the locking pull line , and, when the key cylinder rotates in an unlocking direction that is opposite the locking direction, the unlocking lever pulls the unlocking pull line , and wherein the key operation mechanism further comprises a support component that, when the key cylinder rotates in the locking direction, supports the locking pull line at a position at which the locking lever is at a greater distance away from the support component , and, when the key cylinder rotates in the unlocking direction, supports the unlocking pull line at a position at which the unlocking lever is at a greater distance away from the support component , characterized in that the support component is fixed to a housing and further includes a base plate screwed to an inner surface of the housing , an unlocking cable mounting wall and a locking cable mounting wall , the unlocking cable mounting wall and the locking cable mounting wall both projecting from the base plate toward the inside of the automobile. <EOS>