PROBLEM TO BE SOLVED: To provide a developing apparatus capable of immediately agitating a toner supplied to a two-component developer surface, for promptly mixing the toner homogeneously into the two-component developer. SOLUTION: Since one end of a paddle 23 is disposed, at a position slightly away from immediately below a toner supply opening 18, a toner ends up being dropped from the supply opening 18 to the vicinity of one end of the paddle 23. When the puddle 23 is rotated, the toner on the two-component developer surface is once pumped up, together with the two-component developer in the vicinity thereof by fins 23a of the puddle 23. Subsequently, the toner and the two-component developer are dropped from the fins 23a of the puddle 23 so that the toner lump is solved by the impact, at the time of dropping onto the two-component developing agent surface. According to the rotating motion of the puddle 23, pumping up and dropping of the toner and the two-component developer are repeated so that the toner on the two-component developer surface is agitated directly, while the toner lump is solved. COPYRIGHT: (C)2008,JPO&INPIT