The present invention provides a protection net apparatus fixed to a baby chair having a tray, comprises: a plurality of net supporting parts fixed to different positions of the tray and each including a clamp portion fixing the net supporting part to the tray; and a supporting rod portion coupled to the clamp portion and extending outwards; a net part including a net with an edge having an inner edge, an outer edge located on an opposite side of the inner edge, and lateral edges each connecting between ends of the inner edge and the outer edge; and a receiving pocket attached to the net on an outer edge portion adjacent to the outer edge in a direction that an opening of the receiving pocket heads toward the inner edge and receiving a top end of the supporting rod portion through the opening.