There is disclosed an open showcase provided with a light device capable of simplifying a maintenance operation and improving a cooling efficiency in a display chamber. In an open showcase 1 of the present invention, a display chamber 11 is formed in an insulating wall 2 to display commodities in the display chamber 11 while cooling the commodities, the showcase includes a reflective plate 45 which extends externally from a front surface opening 12 of the display chamber 11, and LED lights 40 attached to the reflective plate 45, and the inside of the display chamber 11 is illuminated with light emitted from the LED lights 40.