Fine art painter and draughtsman. In the age of two, the Kowner family had reached Lodz.
His first painting education was in Kiev (1912-13), then in Dusseldorf (1917-18). During 1919-1939 he again lived in Lodz. He was a member of Group of Artist named Start, he also joined the editorial board of journal entitled Forma, which was dedicated to fine arts. Public presentation of his works of art started at the Municipal Gallery in Lodz in 1928. Later he took part in several exhibitions (1932, 1936, 1937, and 1939). He was moved to the Litzmanstadt Ghetto, then in 1944 transported to Auschwitz. Kowner belonged to small group of Jewish artists from Lodz who survived the German occupation. After the World War II he travelled to Sweden when after a period of convalescence he became a teacher of fine arts.
He was an author of symbolic compositions, still-lifes, and landscapes especially presented courts and architecture of Lodz.