A latch device for an access panel door comprises an open lever and a ratchet release lever which are pivotally mounted on a base plate by a first shaft, a coupling spring to resiliently link the open lever to the release lever, a door detection lever being rotated in response to abutment against a rear panel of a front door, and a lock lever pivotally mounted on the plate by a second shaft and displaceable in response to the rotation of the detection lever. The lock lever is configured so as to mechanically abut against the ratchet release lever when displaced to a locked position and be able to restrict the rotation of the release lever. The coupling spring has a first leg to urge the open lever to a first direction and a second leg to bias both of the open lever and the release lever to a second direction.