A door lock device for use with a striker, comprises a cover plate having an elongate cut into which the striker is insertable. A latch plate is pivotally connected to the cover plate, which is capable of taking a latching position wherein the latch plate is engaged with the striker. A locking plate is pivotally connected to the cover plate, which is capable of taking a locking position wherein the locking plate is engaged with the latch plate to restrain the same at the latching position. A reinforcing shaft is secured to the cover plate and has an enlarged flange formed on a leading end thereof. The above-mentioned parts are so arranged that at least a part of the locking plate is placed between the cover plate and the enlarged flange when the locking plate is in the locking position.