A disco ball with an outer skin (3) which on the outside is fitted with mirror pieces (6) and has an expandable inner structure (2) comprising an inflatable inner skin which in expanded state is spherical and holds the outer skin (3) in a ball shape, characterized in that the outer skin (3) has a plurality of approximately lenticular segments (4) which are arranged next to each other, and adjacent lenticular segments (4) are releasably connected together to form the outer skin (3), and the lenticular segments (4) are each fitted with mirror pieces (6) on the outside.