Disclosed is an apparatus for opening/closing a door in which the door can be semi-automatically closed in a preset section so as to enable an operator in an operating cab to easily close the door. The apparatus for semi-automatically opening/closing door of construction equipment according to the present invention comprises: an upper hinge mounted on the door and having a first receiving hole; an upper option pin which is detachably coupled to a bottom surface of the upper hinge and the bottom surface of which has a first plane and a first inclined surface extending from the first plane; a lower hinge mounted on an operating cab and having a second receiving hole; a lower option pin which is detachably coupled to an upper surface of the lower hinge and the upper surface of which has a second plane and a second inclined surface extending from the second plane; and a guide pin, the upper end of which penetrates through the upper option pin and is coupled to the first receiving hole of the upper hinge, and the lower end of which penetrates through the lower option pin and is coupled to the second receiving hole of the lower hinge.