A cylinder lock protection apparatus, comprising: a housing adapted to be provided above a rotor in which a key hole (Ra) for inserting and pulling out an ignition key is formed; a shutter which is movable between a closing position and an opening position within the housing and adapted to close the key hole (Ra) at the closing position and to open the key hole (Ra) at the opening position; urging means adapted to normally urge the shutter toward the opening position; engaging means adapted to be capable of engaging the shutter existing at the closing position; and releasing means (5, 6) adapted to release engagement made by the engaging means to move the shutter from the closing position to the opening position using an urging force given by the urging means, wherein the releasing means (5, 6) includes manually releasing means for manually releasing the engagement made by the engaging means and remote-controllably releasing means drivable by remote control for releasing the engagement made by the engaging means, and the manually releasing means and the remote-controllably releasing means respectively are capable of operating the engaging means to thereby operate the shutter; and wherein the engaging means is a single member including a first portion adapted to receive the operation force of the manually releasing means and a second portion adapted to receive the drive force of the remote-controllably releasing means; characterized in that the engaging means is capable of being turned about a given shaft, while the first portion is formed on one end side of the engaging means and the second portion is formed on the other end side thereof. a housing adapted to be provided above a rotor in which a key hole (Ra) for inserting and pulling out an ignition key is formed; a shutter which is movable between a closing position and an opening position within the housing and adapted to close the key hole (Ra) at the closing position and to open the key hole (Ra) at the opening position; urging means adapted to normally urge the shutter toward the opening position; engaging means adapted to be capable of engaging the shutter existing at the closing position; and releasing means (5, 6) adapted to release engagement made by the engaging means to move the shutter from the closing position to the opening position using an urging force given by the urging means, wherein the releasing means (5, 6) includes manually releasing means for manually releasing the engagement made by the engaging means and remote-controllably releasing means drivable by remote control for releasing the engagement made by the engaging means, and the manually releasing means and the remote-controllably releasing means respectively are capable of operating the engaging means to thereby operate the shutter; and wherein the engaging means is a single member including a first portion adapted to receive the operation force of the manually releasing means and a second portion adapted to receive the drive force of the remote-controllably releasing means; characterized in that the engaging means is capable of being turned about a given shaft, while the first portion is formed on one end side of the engaging means and the second portion is formed on the other end side thereof.