The present invention provides a mounting device for a heating component, which positions and fixes a heating component together with a heat radiating component, wherein the heating component is provided with a light emitting component, etc. A movable base (2) is provided with an optical unit with the light emitting component. A rear part of the optical unit (10) is provided with the heat radiating component (20). A holder (30) (30) is fixed on the movable base (2). A supporting part (36) and an elastic pressing part (38) of the holder (30) enter a space between an abutting part (21) and an opposite part (22) of the heat radiating component (20). When the holder is disengaged from the movable base (2), the elastic pressing part (38) is pressed by the abutting part (21) and presses the supporting part (36) on the opposite part (22) through a counterforce of the elastic pressing part. The heat radiating component (20) and the holder can be treated for not being disengaged. If a holding part (31) of the holder (30) is fixed on the movable base (2), the flexibility amount of the elastic pressing part (38) is increased for forcefully pressing the abutting part (21) on the optical unit (10).