A developing cartridge comprising: a casing (31, 131, 231) configured to accommodate toner therein; a developing roller rotatable about a developing axis extending in a first direction, the developing roller being positioned at one end portion of the casing (31, 131, 231) in a second direction crossing the first direction; a developing memory having an electrical contact surface facing in a third direction crossing the first direction and the second direction; an agitator rotatable about an agitator axis extending in the first direction and configured to agitate the toner accommodated in the casing (31, 131, 231); an agitator gear positioned at one end of the agitator in the first direction and rotatable about the agitator axis together with the agitator; a holder (52, 152, 252) holding the electrical contact surface and movable relative to the casing (31, 131, 231) in the third direction between a retracted position (Figs. 4A, 7A, 11A, 12A) and an advancing position (Figs. 4B, 7B, 11B, 12B), a distance in the third direction between the electrical contact surface and the agitator axis at the advancing position of the holder (52, 152, 252) being greater than a distance in the third direction between the electrical contact surface and the agitator axis at the retracted position of the holder (52, 152, 252); a plate (55, 155, 255, 355) movable in the second direction relative to the casing (31, 131, 231) between a first position (Figs. 4A, 7A, 11A, 12A) and a second position (Figs. 4B, 7B, 11B, 12B), the second position being closer to the developing roller than the first position is to the developing roller in the second direction, the holder (52, 152, 252) being movable from the retracted position to the advancing position in response to a movement of the plate (55, 155, 255, 355) from the first position to the second position, the plate (55, 155, 255, 355) being positioned farther away from the developing roller than the agitator gear and the holder (52, 152, 252) are from the developing roller in the second direction; and an interlocking mechanism (100, 200, 300, 400) connected to the plate (55, 155, 255, 355) and to the holder (52, 152, 252), the interlocking mechanism (100, 200, 300, 400) being configured to place the holder (52, 152, 252) at the retracted position in a state where the plate (55, 155, 255, 355) is at the first position, and to place the holder (52, 152, 252) at the advancing position in a state where the plate (55, 155, 255, 355) is at the second position, and characterized in that the interlocking mechanism includes a cam movable in association with movement of the plate between the first position and the second position, the cam being in contact with the holder to move the holder between the retracted position and the advancing position. a casing (31, 131, 231) configured to accommodate toner therein; a developing roller rotatable about a developing axis extending in a first direction, the developing roller being positioned at one end portion of the casing (31, 131, 231) in a second direction crossing the first direction; a developing memory having an electrical contact surface facing in a third direction crossing the first direction and the second direction; an agitator rotatable about an agitator axis extending in the first direction and configured to agitate the toner accommodated in the casing (31, 131, 231); an agitator gear positioned at one end of the agitator in the first direction and rotatable about the agitator axis together with the agitator; a holder (52, 152, 252) holding the electrical contact surface and movable relative to the casing (31, 131, 231) in the third direction between a retracted position (Figs. 4A, 7A, 11A, 12A) and an advancing position (Figs. 4B, 7B, 11B, 12B), a distance in the third direction between the electrical contact surface and the agitator axis at the advancing position of the holder (52, 152, 252) being greater than a distance in the third direction between the electrical contact surface and the agitator axis at the retracted position of the holder (52, 152, 252); a plate (55, 155, 255, 355) movable in the second direction relative to the casing (31, 131, 231) between a first position (Figs. 4A, 7A, 11A, 12A) and a second position (Figs. 4B, 7B, 11B, 12B), the second position being closer to the developing roller than the first position is to the developing roller in the second direction, the holder (52, 152, 252) being movable from the retracted position to the advancing position in response to a movement of the plate (55, 155, 255, 355) from the first position to the second position, the plate (55, 155, 255, 355) being positioned farther away from the developing roller than the agitator gear and the holder (52, 152, 252) are from the developing roller in the second direction; and an interlocking mechanism (100, 200, 300, 400) connected to the plate (55, 155, 255, 355) and to the holder (52, 152, 252), the interlocking mechanism (100, 200, 300, 400) being configured to place the holder (52, 152, 252) at the retracted position in a state where the plate (55, 155, 255, 355) is at the first position, and to place the holder (52, 152, 252) at the advancing position in a state where the plate (55, 155, 255, 355) is at the second position, and characterized in that the interlocking mechanism includes a cam movable in association with movement of the plate between the first position and the second position, the cam being in contact with the holder to move the holder between the retracted position and the advancing position.