To secure perfect crime prevention associated with a door device having an entrance door etc. equipped with an auxiliary door for use in the carrying-in of an article, while enabling mischief from the outdoor to be prevented.

An auxiliary door 2 allowing only an article to be passed is provided in a part of a door body 1. The auxiliary door 2 comprises: an outer door 22 provided on an outdoor side of the door body 1, rotated around a rotation shaft 22b mounted on a side end surface and laterally projected, and opened to the outdoor side; an inner door 23 provided on an indoor side of the door body 1 and opened to the indoor side; a middle door 24 provided between the outer door 22 and the inner door 23 of the door body 1, having at least a part through which an outdoor is visible, and opened to the outdoor side or the indoor side; and a middle door lock part locking closing of the middle door 24. The outer door 22 and the inner door 23 of the auxiliary door 2 have fulcrums at their lower ends and opening sides in their upper parts, and form a same horizontal plane at their opening limits. The outer door 22 and the inner door 23 of the auxiliary door 2 have stopper projections engaged with a surrounding member below the fulcrums at their opening limits.