An apparatus for alternatively disinfecting an object surface and a liquid comprising a hollow handle base graspable in a human hand, an electrical power source contained within a hollow interior space of the handle base housing for supplying electrical power to an ultraviolet lamp, a lid including a lamp support bulkhead, and an ultraviolet lamp mounted to the lamp support bulkhead. A tubular cover shell is releasably attachable to the lamp support bulkhead. The cover shell has an upper wall which is opaque to ultraviolet radiation and a lower wall which has therein an aperture which is transmissive to ultraviolet radiation. A hinge joint pivotably joins the lamp support bulkhead of the lid to the handle base housing, the hinge joint enabling the lid to be pivoted from a first, compact storage and transport orientation in which the lower wall of the lid cover shell overlies the handle base housing, and the upper wall of the lid cover shell overlies the ultraviolet lamp to a second, use orientation in which the lid is positionable above an object surface to thereby locate the aperture adjacent to the object surface. The cover is alternatively releasably removable to expose the ultraviolet lamp and enable it to be immersed in a liquid to disinfect the liquid. Sensor probes protrude from the bulkhead near the ultraviolet lamp prevent operation of the lamp unless the probes are in contact with a liquid.