Powder chamber (10) for an air polishing device (80), extending from a top end (t) to a bottom end (b) along an axis (c), said powder chamber (10) comprising at least two wall sections (11； 12), wherein a first wall section (11) forms a first angle (± 11 ) with respect to the axis (c), and wherein a second wall section (12) forms a second angle (± 12 ) with respect to the axis (c), wherein the angles (± 11 , ± 12 ) are measured in a measuring direction (md) from the axis (c) to the appropriate wall section (11； 12) in such a manner so that the acute angles are obtained, wherein the measuring direction (md) from the top end (t) to the bottom end (b) is counted positive, and wherein the measuring direction (md) from the bottom end (b) to the top end (t) is counted negative, wherein the second wall section (12) is arranged below the first wall section (11), and wherein the second angle (± 12 ) is smaller than the first angle (± 11 ).
