<p>A small-sized door lock device capable of reliably preventing a key lever from operating into a lock direction when impact force is applied from a side of the vehicle. The door lock device has a housing (12) for receiving an operation mechanism (13) and having formed on it a support section (12f) for rotatably supporting a key lever mechanism (29). The key lever mechanism has a first engagement section (31) formed at a support end section (12f1) of the support section and also has a second engagement section (32) facing the support end section of the support section, rotatably supported by the support section, and engaging with the first engagement section to prevent rotation of the key lever mechanism in the lock direction. The key lever mechanism is adapted so that the first engagement section and the second engagement section are engaged with each other when the second engagement section moves in the direction to approach the support end section of the support section.</p>
