The present invention relates to a seeding seed supply apparatus having a seed-releasing chamber, wherein a side frame is provided on each side of a conveyor for transporting a seedling, and a hopper for storing a seed for seeding on the upper side of the side frame, And an opening / closing plate provided on a lower side of the hopper, the opening / closing plate being opened / closed by an operating lever and discharging the seed to the lower side, the apparatus for supplying seed for seeding into a seedling box, A plurality of circular rotating plates of the same shape in which the mounting grooves are formed at regular intervals along the outer periphery, a plurality of projecting portions formed on one side, and a plurality of projecting portions formed on the other side A plurality of grooves corresponding to the protruding portions of the coupling-side inner side portions are formed, A pair of side frames each of which is fixed to a pair of support shafts fixed to the inside of the pair of side frames and is biased toward the seed feed direction on the lower side of the feed roller, A seed removing blade provided on the lower side of the feed roller in the longitudinal direction of the feed roller between the plurality of circular rotary plates to separate the seeds adhering to the feed roller and a seed removing blade disposed on the upper side of the feed roller, A brush connected to the supply roller and rotationally driven in the same direction as the supply roller, a brush connected to the supply roller and provided on an axis of the supply roller outside the one side frame for axially rotating the supply roller and the brush, A sprocket, a chain connected to the sprocket, and a first motor for driving the chain, A sprocket provided on an axis of the feeding roller to the outside of the frame, a chain connected to the sprocket, a plurality of sprockets connected to the chain and chain-connected to each other along a frame in which the conveyor is install
