Abstract: In combination with a building door, there is provided a key safe for a door key comprising an open ended housing secured within and projecting through the door. A safe door is hinged to and closes one end of the housing and has a retractable latch bar engageable with the building door to lock the safe door. A combination lock on the safe door includes a normally open printed circuit connected to a power source. A solenoid is connected to the circuit and includes a plunger connected to the latch bar. A tamper proof key tray is nested within the housing and normally spring biased for ejection inwardly of the building door. A first detent assembly is interposed between the safe door and tray so that any forceful opening of the safe door disengages the detent assembly.