Downlight apparatus

A downlight apparatus, comprising:

• a fixing bar with two elastic units and a central part, wherein the two elastic units are located at two opposite sides of the central part, wherein the two elastic units are deformed so as to pass through a central hole of a fixing plate and then are released to attach to the fixing plate, wherein the fixing plate is fixed to a platform;
• a driver box comprising a driver for converting an external power to a driving current;
• a light container with a top cover and a lateral wall, wherein the fixing bar is fixed on the top cover protruding toward the central hole of the fixing plate, wherein a bottom side of the driver box is placed on the central part;
• and
• a light source placed inside the light container to receive the driving current to emit a light from a light opening of the light container, wherein a protruding edge is disposed on an inner surface of the lateral wall for selectively attaching one of at least two types of light passing covers, wherein the at least two types of light passing covers comprise a first light passing cover and a second light passing cover, wherein the lateral wall defines the light opening, wherein the first light passing cover conceals the light opening, wherein a first diameter of the first light passing cover is smaller than a peripheral diameter of the lateral wall, wherein the second light passing cover conceals the light opening, wherein the second light passing cover conceals a bottom of the lateral wall.