To improve a crime preventing property while imparting good designability by preventing a door of a building from being removed when it is locked, which door is connected to a side of a skeleton to be swingingly openable by using a pair of hinge pieces adjacent to each other in a vertical direction.

The door-side hinge element 4 is screwed and fixed to a door-side liner 9D provided on the inside of a hanging-side face 1a of an entrance door 1. The skeleton-side hinge element 5 is screwed and fixed to a hanging-side vertical frame body 2b of a door frame body 2 by using a frame-side liner 9F. A projection 8 is screwed and fixed to the door-side liner 9D using a through hole 4d for the projection formed in the door-side hinge element 4. A recess part 10 is formed in the hanging-side vertical frame body 2b of the door frame body 2 so that the projection 8 may be fitted thereinto and may prevent the door from being removed.