Proposed is a hinge device having tension maintaining function, the hinge device including: a winding member affixed to a main body of a mounted structure having an inner space formed therein; a hinge member affixed to a door that opens or closes the inner space and mounted on the winding member so as to enable the door to be pivotable; and a tension member having one end affixed to the winding member and the other end affixed to the hinge member, such that the tension member transmits a tension to the door when opening and closing the door.